"Via Alsace" stamp
Between 1872 and 1874 (the last known date), some letters sent to Switzerland bore the marking "VIA ALSACE."
A brief analysis of these letters reveals that:
They generally originated from the northern half of France or from northern countries where France facilitated postal transit to Switzerland.
All were either insufficiently franked or completely unfranked.
They entered Switzerland via Basel.
Letter from LILLE to DAGMARSELLEN (Switzerland) with insufficient postage at 25 c.
The rate for Switzerland had been 30c since 1 October 1865. The Franco-Swiss postal convention of 22 March 1865 stipulated that in the case of a letter with insufficient franking, The tax to be charged to the addressee was the difference between the postage for a postage due letter (50 c) and the amount of the stamps affixed to the letter. However, if the tax was a fraction of a decimal, it had to be rounded up to the next decimal. So here we have:
- tax on the letter without postage: 50 c
- postage due: 25 c
- tax payable 50 c - 25 c = 25 c rounded up to 30 c.
The "VIA ALSACE" Postmark in Franco-Swiss Postal Relations (1872–1875).
The Franco-Swiss postal agreement of 1865 established two main dispatch routes for French mail to Switzerland: SAINT-LOUIS and PONTARLIER.
However, from 1871 onwards, Franco-Swiss postal relations faced a new complication: Germany.
With the annexation of France’s eastern departments by Germany, France could still send mail to Switzerland via PONTARLIER. However, to maintain a more direct and frequently serviced route for mail from the northern half of France, an alternative was needed.
On 15 February 1872, the route to Basel was reopened, now passing through BELFORT (instead of SAINT-LOUIS) and annexed Alsace (Monthly Bulletin no. 35, February 1872).
Increased Costs Due to Transit Through Alsace.
This rerouting through Alsace increased transportation costs and transit duties payable to Germany. While French costs remain unknown, Switzerland, for example, paid 11,700 francs more in 1872 than in 1871 for mail transit via Alsace (Federal Council Report, 1872, p. 163). In 1873, Switzerland still paid Germany 20,700 francs in transit fees (Federal Council Report, 1873, p. 37).
Swiss or French Stamp?
Primary sources do not provide a definitive answer, but the "VIA ALSACE" postmark was likely a Swiss accounting mark, probably applied in BASEL, to identify the route taken and ensure the correct country—Germany—was compensated.
France had no reason to mark the route of outgoing mail to Switzerland. If anything, such a marking might have been useful for mail coming from Switzerland to France, yet this postmark is never found on Swiss-origin letters to France.
For insufficiently franked or unfranked letters, Switzerland needed a way to track the route taken because it had to share part of the postage due either with France (if the mail passed through PONTARLIER) or Germany (if it transited via Alsace).
When Was the Postmark Introduced?
Its exact introduction date is uncertain, but it likely appeared with the enforcement of the Franco-German postal convention of February 1872, which took effect on 22 May 1872. The Swiss Federal Council’s 1872 report (p. 139) listed the "introduction of direct mail exchanges with France via Alsace, in application of the agreement between Germany and France" as one of the year’s key postal decisions.
The earliest known letter bearing the "VIA ALSACE" postmark dates from December 1872.
The latest known letter, sent from COMPIEGNE, is dated 23 September 1875.
The Disappearance of the Postmark.
The discontinuation of this postmark is poorly documented. However, it likely fell out of use when France joined the General Postal Union (GPU) on 1 January 1876, following Switzerland and Germany’s accession on 1 July 1875. This global postal integration likely led to a revision of inter-country transit duties, rendering such accounting marks obsolete.
Rarity of the "VIA ALSACE" Postmark.
This postmark is likely very rare, as it was only applied to letters with insufficient or no postage. At the time, the vast majority of mail to Switzerland was fully prepaid. Furthermore, it was specific to only one route—from Belfort to BASEL—further limiting its use.
