Letter Mail: France and Belgium

The Project
Postal agreements prior to the General Postal Union/Universal Postal Union in 1875 were highly diverse, though they show increased uniformity over time from 1850 to 1875 in Europe.  This post focuses on mail between France and Belgium beginning with the 1847 postal convention between these nations.  Last edited: Mar 2, 2021

Organization of this Post

• Postal Arrangements Prior to 1847
• Postal Arrangements from 1847 - 1875
  
• Prepaid Letter Mail France to Belgium
• 1857 Convention Prepaid Letters
  
• 1865 Convention Prepaid Letters
  
• Belgium to France Prepaid Rates 
• 1857 Convention Prepaid Letters
• 1865 Convention Prepaid Letters
  
• Border Mail 
• 1857 Convention Border Rate Paid
  
• Border Crossings  
• Notes About Railways and Exchange Offices
  
• Belgium Frees Itself from the Netherlands
• Resources and Links
• Related Blog Posts

Postal Arrangements Prior to 1847

Postage between Belgium and France was the total of the combined domestic rates.  Both countries used weight and distance components to calculate the postage due.  It was not possible to prepay postage for a letter between nations at this time.  

Rather than cite the postal instructions of the time, I will simply illustrate a folded letter that falls under this postal arrangement.

Item #1 - Unpaid letter from Bruxelles to Bordeaux 1845

Bruxelles Dec 11, 1845 Belg Valenciennes Dec 13 B.3.R. (in green) Bordeaux Dec 15, 1845 (verso) Bordeaux Dec 16, 1845 (verso) "14" decimes due at Bordeaux

This item is discussed in detail in this blog post.   It was also featured on Postal History Sunday for Oct 25, 2020.

Belgian postage: 4 decimes 

On January 10, 1831, the powers of Europe ratified Belgium’s declaration of independence, but the postal agreement operating between France and Belgium was essentially based on the 1828 agreement with the Netherlands of which Belgium had been a part.  There were three distances (rayons) in Belgium with the third rayon requiring the highest rate of 4 decimes.  

French postage: 10 decimes

French domestic rates were based on distance and weight.  The distance would be from the border with Belgium (roughly Valenciennes) to Bordeaux (nearly 800 km).  

The internal French postage rate for 7.5 grams established in January of 1828 was 1 franc (100 centimes) for internal mail that traveled 750 to 900 km.  

Postal Markings for postage calculation
B.3.R.
      Belgium 3rd Rayon
rate = 40 centimes / 10 grams
           for 60 - 100 km

French Postage
rate = 1 franc / 7.5 grams
           for 750-900 km

The effective period for this agreement governing letter mail from Belgium to France was Jan 10, 1831 to Sep 30, 1849

Postal Arrangements from 1847 - 1875

Postage rates between these two countries removed the distance component of the rate structure with the exception of special discounted rate for border communities beginning with the 1857 agreement.  Also in 1858, higher rates for unpaid and short-paid mail were implemented to encourage prepayment of postage

Rates between France, Italy, Switzerland and Belgium are simpler to understand as they worked their way towards the "Latin Monetary Unit" in 1865.  (Greece joined this group in 1868)  From a postal history perspective, this is at least partly responsible for our being able to say that the rate in each direction was the same (without needing to convert currency).

Postal Agreement of November 3, 1847
This agreement allowed payment to destination, payment to the border or payment by the recipient (sent unpaid).  Belgium was split into districts (rayons) to determine rates.  Also, the rate progression by weight was not a linear progression.  Note that the first rate actually differs for the weight limit between Belgium (10 grammes) and France (7.5 grammes).  See Article 7 and 8 for details on this progression (shown below).  This agreement sets the tone for future agreements, which make the rates simpler for letter mail.

Convention of 1847

Article 7 & 8	Article 1	Articles 12-14
Rate Progression	Exchange Offices	Foreign Mail Routing

Click on the text image to see a larger version.

Exchange offices were initially set forth in this treaty, with most exchanging mail once per day and carrying local mail (such as Dunkerque and Furnes).  It is likely the number of mails changed over time into the 1860's just as the list of exchange office pairings, etc increased.  As rail traffic increased, the schedule of mail exchanges also increased, reflecting the actual train schedules.

1847 Exchange Offices

3 mails per day	2 mails per day	1 mail per day
Lille - Tournai	Valenciennes - MIDI Lille, Roubaix, Tourcoing - Courtrai, Gand, TPO L'Ouest	Paris - MIDI, TPO L'Ouest Trelon - Chimay Thionville - Arlon Sedan - Bouillon Roeray - Couvin Montmedy - Virton Maubauge - Mons Longwy - Arlon Givet - Dinant Dunkerque - Furnes Avesnes - Mons, Chimay

French offices are first in each pairing

Postal Agreement of 1849
Other than the exception of border communities, distance was no longer a part of the rate calculation.  I am guessing the rate was now a linear progression, though it would be nice to confirm this.  Oddly, I have not yet found the text of this convention.

 

This convention did not become effective until October 1, 1849.  Not a surprise given the political upheaval in France at the time.

Postal Agreements of 1857 and 1865
The 1857 convention clearly broke more ground than the 1865 convention, which cites the 1857 convention throughout.  The rate was reduced from 40 centimes to 30 centimes per 10 grams.   No changes were made to border mail in the 1865 convention, so 1857 processes still applied.

Conventions of 1858 and 1866

Article 1.4 - 1857 Rate Progression	Article 1.5 - 1857 Border Mail Rate	Article 1 - 1865 Rate Progression

Click on the text image to see a larger version.

Prepaid Letter Mail: France to Belgium

Prepaid Letter Rates - France to Belgium

Effective Date	Rate	Unit
Oct 1, 1849	40 centimes	7.5 grams (a)
Apr 1, 1858	40 centimes	10 grams
Jan 1, 1866	30 centimes	10 grams
Jan 1, 1876 (GPU)	30 centimes	15 grams
May 1, 1878 (UPU)	25 centimes	15 grams
Oct 1, 1907 (UPU)	25 ctm / 15 ctm	15 g / add'l 15 g

(a) - rate increments for weight may not have been linear and would require a second table if that was the case.  Still seeking confirmation of rates and convention details.

1857 Convention Prepaid Letters

40 centimes per 10 grams: Apr 1, 1858- Dec 31, 1865

Prepaid letter mail from France to Belgium was marked with the letters "PD" to indicate that the postage had been paid in full to the destination (payée à destiné).  France typically applied their paid markings in red ink.

Also, most letters included a postmark from a designated exchange office where it was placed in the mailbag in France and then removed from the mailbag for processing in Belgium.  The valid pairing of exchange offices expanded over time and did not require modifications to postal conventions. 

Many of these exchange offices were actually in railway cars as the mail traveled from one location to the next. 

Item #2 - Paid letter from Cambrai to Tournay 1860

Cambrai May 18, 1860      593 in diamond grid      PD in box      Apres Le Depart France par Tournay May 20

Cambrai,France and Tournay, Belgium served as the exchange offices for this letter.  The exchange office pairing can often give a suggestion as to the actual route this letter took as it crossed the French/Belgian border.

Cambrai is located Southwest of Valenciennes, yet this item appears to have gone to Lille and then Tournay given the "France par Tournay" marking.  One could make the argument that the Tournay destination resulted simply in a Tournay exchange marking and the letter took a different route to get there.  However, the Apres Le Depart marking lends itself to the idea that the most likely route (Quievrain crossing) was not taken because the item was received after that train had left.  As a result, it took the next train on the schedule that could get the letter to Tournay - perhaps that train through Lille.

1865 Convention Prepaid Letters

30 centimes per 10 grams - Jan 1, 1866- Dec 31, 1875

The procedure of marking letters with the "PD" continued, as did placing exchange markings on the letters as they entered mailbags and then as they were pulled out for processing in Belgium.  

The possible number of routes had grown significantly with the improvements in rail travel.  In fact, many of the markings show a time of day that could allow for identification of a route if an old rail schedule could be located.  The abbreviations M (matin - morning) and S (soir - evening) tell you which half of the day the number applies to.  5M would be 5 AM.

Item #3 - Lille to Bruxelles 1868

Lille 25 Apr 68       PD in box France MIDI I 26 Apr 68 (verso) Bruxelles 26 Apr 68   (verso) St Gilles . Bruxelles 26 Apr 68 (verso)

This item has its origin at Lille, which is very near the border with Belgium.   I assume this took the Lille-Tournay crossing at Tourcoing but it did not receive an exchange office marking until it arrived at MIDI station since the destination was near Bruxelles at St Gilles. 

A MIDI exchange marking could pair with a wide number of border crossings.  With the Lille origin, this could very well, given the right rail schedule, have gone via Valenciennes or Quievrain. However, the simplest and most likely explanation would be the Tourcoing crossing with a significant number of mails being made up every day to go by this route.  The mail train would simply turn East towards Tournay after crossing the border and continue North to Bruxelles.

Item #4 - Arras to Gand 1867

Arras June 13, 1867      PD in box France MIDI I  -  Jun 14, 1867 Gand 8M - Jun 14, 1867      7 in circle       - carrier/delivery marking

Arras is located west of the rail line split, so there was a choice between Lille (Tourcoing) or Valenciennes (Quievrain) for routing.  My guess is that this hitched a ride aboard the mail train from Paris and a trip through Valenciennes.  The MIDI I exchange supports a Quievrain crossing since there wouldn't be much cause to go through Bruxelles to get to Gand (Ghent) if the northern route were taken.

Like many other European cities, Gand/Ghent marked their mail with either a carrier number or some sort of distribution number.  It seems likely that the "7 in circle" would identify a carrier or a carrier route rather than a distribution.  I do not believe Gand would have supported seven different mail distributions.  The only reason this could a distribution number is if their distributions were given a number based on the distribution time. 

Item #5 - Reims to Namur 1868

Reims Feb 10, 1868 Paris A Givet Feb 10 1868 (verso) France Namur Feb 11 68 (verso) Namur Feb 11, 1868

The combination of a Reims origin and a Namur exchange marking makes me believe that this crossed the border in the Ardennes.  That rail connection should have been complete or near completion by 1868.  After comparisons with other similar markings on items I do not own, I can conclude that the rail marking is, indeed, Paris A Givet, which should confirm this routing.  The 11M timestamp on the Namur backstamp gives us information regarding the scheduling of this particular mail train.

Item #6 - Arras to Anvers 1867

Gare D'Arras Sep 21, 1867 Paris A Arras Sep 21 (verso) France Par Mouscron Sep 21 3-4S (verso) Anvers Sep 21 7S (verso)

This item adds a piece to the puzzle that I find refreshing.  The somewhat blurred France Par Mouscron marking on the back of this item provides solid evidence of the Tourcoing crossing since Mouscron was the Belgian town closest to the border on that rail line.  

At Mouscron, the mail could either go north towards Courtray (and on to Gand/Ghent) or east towards Tournay.  It seems most logical to go through Ghent on the way to Anvers/Antwerp. Also of note are the time markings on these backstamps.  3-4S and 7S markings indicate travel after midday and a three to four hour transit time.  This would be consistent with a direct line to Anvers.

Like Item #4 this item originated in Arras.  However, it was mailed at the trainstation (Gare d'Arras) and postmarked with the rail marking "P AR" in a diamond grid.  In both cases, the train could have been routed via Lille or Valenciennes depending on the schedule.  Lille would result in a Tourcoing crossing and Valenciennes would be Quievrain.  The time stamp for the other item in Gand is 8M, while this is 3-4S, which would support a different train schedule between the two.

Prepaid Letter Mail: Belgium to France

The rate table is essentially a duplicate to the France to Belgium rate table.  It is here to allow ease of reference in the post with examples of Belgian mail to France.  Please note that I have NOT confirmed effective dates with postal orders from the Belgian post office.  I am making what could be a bad assumption that they became effective at the same time the rate was placed in effect by France.

Letter Rates - Belgium to France 

Effective Date	Rate	Unit
Oct 1, 1849	40 centimes	7.5 grams
Apr 1, 1858	40 centimes	10 grams
Jan 1, 1866	30 centimes	10 grams
Jan 1, 1876 (GPU)	30 centimes	15 grams
May 1, 1878 (UPU)	25 centimes	15 grams
Oct 1, 1907 (UPU)	25 ctm / 15 ctm	15 g / add'l 15 g

1857 Convention Prepaid Letters
 

40 centimes per 10 grams - 1858-1865

Belgian "PD" markings were most often in black ink, as were the Belgian exchange office markings.  Like France, there were many ambulant (mobile post office on train) offices that served as exchange offices to promote efficient mail transfer.  

France was particularly good with utilizing receiving exchange office markings - typically in red until blue starts showing up more in the late 1860s.  A French receiving exchange office marking usually showed the country from which it came (in this case "Belg"), a date and a route.  The route marking did not always indicate where the marking was applied.  An additional numeral along the rim might indicate a different location where the item was processed, while the location (such as Valenciennes) merely showed the routing.  See Item #9 for an example of this.

Item #7 - Anvers to Paris 1861

Anvers Feb 27 1861 Ambt du Midi No 1 Feb 27 (verso) Belg Valenciennes Feb 28 1861 Paris Feb 28 1861 (verso)

 

This letter is discussed in detail in this blog post.

 

The exchange office combination of MIDI station with Valenciennes, crossing at Quievrain, feels like it carried most mail that filtered through Paris on the French side and Bruxelles on the Belgian side.

  

The Belgian markings give us a time of day with 3S being three o'clock in the afternoon and 7S as four hours later.  

 

Item #8 - Anvers to Paris 1859

 

Anvers Anvers Oct 14, 1859 ? 1859 (verso) Belg Amb Calais Oct 15, 1859 Paris Oct 15, 1859 (verso)

 

This letter also has its own blog post, discussing it in more detail.

 

Here is an item that I find myself wishing someone had not lost the rest of the postal markings so I could explore the routing further.  It is clear that there is at least one, but probably more than one, marking that was applied to the verso that is no longer part of the item.  The partial mark is clearly a Belgian mark that would have given us a clue on the rail transit and crossing that would lead to an Ambulant Calais French marking.  Also, since St Etienne is south of Lyon, there is likely at least one more French marking after the Paris postmark.

Item #9 - Mons to Paris 1864

Mons July 4, 1864 Belg VALnes July 5, 1864 Paris July 5, 1864 (verso)

 

The letter has its own entry in this blog with details regarding the correspondents

 

VALnes was a shortened version of Valenciennes and the "5" in the red circular exchange mark indicates that it was applied in Paris rather than in Valenciennes or on the train from Valenciennes.   The Mons post office in Belgium could exchange mail with the Paris exchange office.  So, this folded letter went into a mailbag in Mons after it had the "5" in diamond dots cancellation applied to the postage stamp and the Mons circular date stamp applied.

Mons is not situated very far from the border and also not very far from Valenciennes.  The actual border crossing is at Quievrain. 

Mons was very much a junction point for many rail lines to various locations within Belgium and two border crossings could be taken directly from the city (the other is Erquilinnes). 

Item #10 - Double rate letter, Ypres to Paris 1865

Ypres, March 19, 1865 France Par Mouscron Mar 19, 1865 (verso) Belg Valenciennes Mar 20, 1865 Paris Mar 20, 1865 (verso)

 

This cover also has its own blog post.

 

Ypres is North and West of Mouscron and no other crossing makes much sense for this place of origination.  That certainly does not preclude another routing, but there were so many trains that went from Mouscron to Valenciennes in a day that I find it highly unlikely that another route would be taken unless there were blockages on the tracks or some other such thing.  Happily, this item confirms the route as well with both a Mouscron and a Valenciennes marking.

We can also get some clues regarding train schedule with the time indicators on the postmarks.  Ypres departure at "2S" and Mouscron departure at "7-8S."  So, the train was scheduled to leave Ypres at 2PM and was at Mouscron between 7 and 8 PM that evening.

 

1865 Convention Prepaid Letters

 
30 centimes per 10 grams - 1866-1875

 

This convention period shows an even wider range of exchange offices early on and then the postal services began the process of simplifying their exchange markings, leading up to the General Postal Union in 1875/76. 

 

Item #11 - Anvers to Calais 1867

 

Anvers Nov 30, 1867 France Par Mouscron Dec 1, 1867 (verso) Belgique Lille Dec 1 1867 Lille Dec 1, 1867 (verso) Calais Dec 2, 1867 (verso)

 

This item clearly goes via the Tourcoing crossing from Mouscron to Lille.  The question as to why a "Lille" exchange versus other choices has to do with train schedules.

 

Item #12 - Charleroy to Charleville 1866

 

Montigny-sur-Sambre (dateline) Charleroy Mar 6, 1866 France par Chimay Mar 6 (verso) Belg Avesnes Mar 6 Equilines A Paris Mar 6(verso) Charleville Mar 7 (verso)

 

This is an example of a less often seen exchange office pairing - Chimay in Belgium and Avesnes in France.  It would be tempting to think this item could qualify for the border rate because both of these post offices were within range to be included on lists for border mail.  But, the distance between these two is about 90 km, not close enough to qualify.

Border Mail

Border Letter Rates **

Effective Date	Rate	Unit
Oct 1, 1849	20 centimes	7.5 grams
Apr 1, 1858	20 centimes	10 grams
Jan 1, 1866	20 centimes	10 grams

** both directions France to Belgium and Belgium to France

A Postal History Sunday blog covered the concept of border mail for several European country pairs, including Belgium and France and may be of interest to readers.

Special reduced rates for border communities were maintained throughout these conventions with the basic guideline that the distance was 30 km or less from the origin post office to the destination post office.  In practice, postmasters at border communities worked from a list of destination post offices that were eligible for this reduced rate.  This is not as onerous as it might sound since postal clerks had previously had to view lists of all sorts to determine distances for all of the mail since that was part of the postage rate determination.

Without doing actual calculations, it would be safe to say that less than 5% of the population for each country lives inside of the area that could qualify for the reduced rate.  On top of that, not all of the mail leaving those areas would go TO a destination that also qualified for the reduced rate.  I think it would be safe to estimate that no more than 1% of all of the letter mail that was sent between Belgium and France would have qualified for these rates.

Border mail still required the indication that an item was fully paid, short paid or unpaid.  So, paid border mail in both directions will show a "PD" marking.
 
The following pieces of the convention illustrate the border mail regulations and provide a list of locations that would benefit from the special rate.

Eligible Border Locations - According to Convention

1849	1858	1866
convention effective Oct 1, 1849	Convention effective April 1, 1858	Convention effective Jan 1, 1866

Click on the text image to see a larger version.

There were numerous small communities that served as mail exchange offices for local border mail.  For example, the 1847 convention lists several exchange office pairings that are clearly for local mails:

• Avesnes (France) with Mons (to its north) and Chimay (to its East)
• Dunkerque with Furnes (on the Channel)
• Givet with Dinant (Ardennes)
• Longwy with Arlon (by Luxembourg)
• Maubauge (between Avesnes and Mons) with Mons
• Roeroy with Couvin (south Ardennes)
• Sedan with Bouillon (southeast Belgium)
• Thionville with Arlon (by Luxembourg)
• Trelon with Chimay (south of Avesnes)
• Tourcoing and Roubaix with Courtray
  

Of course, some of these offices were used for the transfer of other mail, especially as rail lines proliferated.  Avesnes, Givet and Dinant each served more area than the immediate communities that were nearby.

1857 Convention Border Rate Paid

Item #13 -  Courtray to Lille 1865

 

Courtray 10M Mar 28, 1865 France par Mouscron 9-10M Mar 28 (verso) Belgique Lille Mar 28 Lille Mar 28 (verso)

 

The folded letter above traveled from Courtray (Courtrai), Belgium to Lille, France.  The distance between post offices was right on the edge of qualifying at 30 km.  Both communities were fairly good sized, making it more likely that examples of border rate uses between them could be found.

 

It is particularly interesting that there are four postmarks (not including the PD marking).  One for the origin (Courtray), one for the Belgian exchange (France par Mouscron), one for the French exchange (Lille in red on front), and one for the receiving post office (Lille on back of letter). 

Border Crossings

It is instructive to take a look at the border crossings for this time period to get a sense for the routes and corresponding times for mail transfer between the two countries.  Below is a Belgian rail map showing active lines around 1875, this give an overview of what might have been available at various points from the 1840s to 1875.  Click to see a larger version.

 

I will take a moment to discuss each crossing briefly from North to South.

Tourcoing Crossing (Lille, Roubaix, and Tourcoing with Mouscron, Courtray, and Tournay): This crossing served local mails as well as mail from and funneled through Paris.  With significant mail train traffic already between Calais and Paris for mails from England as well as mails across the Atlantic, Lille was an obvious location to either drop off mails intended to enter Belgium or run a train direct from Paris through Lille. 

This crossing was highly utilized even as early as the 1847 convention (and before) with multiple mails being made up to cross the border each day.

Quievrain Crossing (Valenciennes with Mons and MIDI Station): Mail via Valenciennes headed for Bruxelles (and MIDI Station) was also listed in the 1847 as having more than one mail per day.  Especially early on, it is likely mail to/from the western portion of Belgium tended to go via Tourcoing and mail to/from the eastern portion via Quievrain.

As rail schedules and lines expanded, mail to and from the larger population centers would take the mail train that would get the mail to the destination fastest - even if it wasn't the most direct route.

Quevy Crossing (Mauberge and Mons): This rail line was developed later than several of the others and provided another option to get to Mons, which provided multiple options for rail traffic in all directions.  I have not seen a marking for Quevy specifically and anticipate that identifying this crossing for a piece of mail would require rail schedules.

Erquelines Crossing (Mauberge and Jeumont): Also spelled Erquilinnes, this rail line was also developed early, providing access to Liege and the Belgian/Prussian border.  Letter mail to and from Prussia and other countries to the Northeast would often transit Belgium on its way to or from France.  Mails to and from Hannover, Prussia and the Netherlands frequently show a French transit mark for this route.  Occasionally a person can find a cover from the United States that will display this same transit marking. 

Chimay Crossing (Avesnes, Macon and Trelon): This crossing was available as a stage crossing for local mails and the Chimay Railway was developed by private interests, becoming active sometime between 1865 and 1869 according to maps of the area from those periods.

Vireux Crossing (Couvin,Vireux): This rail was also developed in the 1860s and probably carried mostly local and regional mail.

A map from 1861 shows a rail line approaching the peninsula shaped area of France jutting into Belgium in the Ardennes.  The train route in Belgium was open in 1854 to Vireux - Molhain (in France), but there was apparently no adjoining French train by 1861.  The line out of Rheims should have been developed by the mid-1860's.  An 1865 map of Belgium does not show a connection here, but a map by the same producer does show its presence in the 1869 version.  It seems to me that the Givet route would have more value except for local mail.

Givet Crossing (Givet, Dinant): Givet is located further north in the peninsula shaped protrusion of the French border into Belgium.  I have viewed a 1864 ambulatory rail marking for Givet, which seems to confirm completion of the Florennes to Givet line that was completed June 23, 1862.  Once a the full connection was made to Namur, this route could support a Paris mail train that would run East to Aachen similar to the Erquelines crossing. 

Luxembourg Area Crossings (Neufchatel, Arlon, Thionville):  This area might deserve more of my attention in the future.  Thionville was a fairly important exchange office prior to the 1847 convention.  By the time we get into the 1850s, 60s and 70s it seems that mail sent by these routes would be regional in nature.

Notes About Railways & Exchange Offices

(Paris with Gand and TPO L'Ouest) Belgium's western mail lines centered around Gand (Ghent) provided the connection to the port of Ostende, which was critical for Belgium's ability to serve the transit of mail from the United Kingdom and off continent to France and the German states.

Paris could exchange mail with both the Gand office and the traveling Traveling Post Office -  L'OuestThese frequently using the Tourcoing crossing, though this crossing becomes less of a lock as rail line schedules became more complex in the 1860s.

(MIDI Station) It is unclear to me whether the MIDI station exchange markings provide any specific indication as to the route the mailbag took (or was to take).  Those markings that include a time could allow a person to deduce the route with a rail schedule.  MIDI Station exchange marks appear to be one of the most frequently encountered for Belgian/French mail during this period.

I have observed several items leaving Belgium for Spain or Italy that exhibit a MIDI II marking that includes the destination country in the marking. 

Initially, the MIDI was located in Brussels as the station for the early line to Mons.  It was moved to St Gilles (just outside Brussels) in 1864 to handle the higher volume of traffic.  Mail exiting Belgium would likely leave via Mons early on.  But as rail options proliferated, letters leaving the MIDI station could leave at any border (and thus enter from any border).  

By the 1847 convention, the MIDI traveling rail office would exchange with Valenciennes and Paris offices.  Valenciennes was scheduled for two mails in 1847 (and was likely increased later).

Belgium Frees Itself from the Netherlands

 

The Congress of Vienna (1815) essentially attached Belgium to the Netherlands.

ART. LXV. The ancient United Provinces of the Netherlands and the late Belgic provinces, both within the limits fixed by the following Article, shall form, together with the countries and territories designated in the same article, under the sovereignty of his Royal Highness the Prince of Orange-Nassau, sovereign prince of the United Provinces, the kingdom of the Netherlands, hereditary in the order of succession already established by the Act of the constitution of the said United Provinces. The title and the prerogatives of the royal dignity are recognised by all the Powers in the house of Orange-Nassau.  

[from General Treaty/Final Act of the Congress of Vienna, June 9, 1815 - note that this is actually before the Battle of Waterloo]

On October 4, 1830, Belgium declared independence from the Netherlands.  The current powers of Europe intervened and ratified this on January 10, 1831.  The final treaty signed on Oct 15, 1831 left Luxembourg with the Netherlands and recognized Belgium, but Netherlands refused to sign that treaty.  War persisted between the Netherlands and Belgium for eight more years.  A second treaty (Treaty of London - 1839) signed April 19, 1839 set the boundaries that would be in use when postage stamps began to see use.  These borders, interestingly enough, were fairly similar to those found in 1790.

Resources

 

Les Tarifs Postaux Francais: Entre 1848 et 1916 by Jean-Louis Bourgouin
     My "go to" site for determining French rates.  Data appears to be backed up by postal acts and agreements.

Duvergier,  Jean Baptiste, "Collection complete de lois, decrets, d'interets general ... par France"
  After a much appreciated suggestion by Laurent on the altpostgeschichte forum, I can now provide links to the French version of both the 1858 and 1866 convention documents.
1857: Is in volume 58
1865: Is in volume 65

Greuse (ed.), "Recueil des traites et conventions concernant le royaume du Belgique," 1850.
   Here we have the Belgian counterpart for treaty and convention texts.  Page 545 includes the 1847 version of exchange offices between France and Belgium.

General Treaty/Final Act of the Congress of Vienna, June 9, 1815
     Actual treaty text in English (language used for official documents was French - the language of diplomacy at that time).  It is located on WikiSource which is getting better at providing access to the text of original documents such as this.  It is instructive to read how this treaty set up Europe after the defeat of Napoleon at Waterloo (which was not at all certain at the time of the Congress of Vienna).

LeBecque, Emmanuel, Histoire Postale du Nord, 2014
   Lebecque includes several portions of conventions and official postal acts that apply to his area of interest.  The three sections for border mail are included on his site and I have "shamelessly" taken them for the purpose of illustrating the border mail rate from the French perspective. 

Kevers, Paul - Belgian Rail Lines
    There is a great deal of work here identifying each spur and its development.  I am inclined to trust what appears to be a pure labor of love in the effort of accumulating this information, but I have not spent time confirming the dates shown there.  There is even an animation to show development of lines in Belgium to 1855.

Busschots, Bart - Belgian Railway History Project
   This takes it all to a new level.  Mr. Busschots gives credit to Mr. Kevers to get him going.  But, now he is using Google maps to try and identify the actual historical locations of the rail beds.  While I haven't had the time to download the software required, I may just find the time and bandwidth to do so just to see his work.

History of the Gare du Midi District
   For a site that is concerned about providing current information and status of the projects in this district, it certainly has a decent historical summary. 

von Adolphe Hochsteyn, Dictionnaire-postal de la Belgique, up to 1845.

Related Blog Posts

• Letter Mail: France and the Netherlands
• French Postal Agreements
• Writing Home to Family - Postal History Sunday
•  Borderline Benefits - Postal History Sunday
• also note links for specific covers linked below their image (when they exist)