At the Potsdam Conference in August 1945, after Germany's unconditional surrender on May 8, 1945, the Allies divided Germany into four military occupation zones – French in the southwest, British in the northwest, United States in the south, and Soviet in the east. According to the agreement, the occupiers would "possess supreme authority with respect to Germany."
The French zone consisted of the present state of Rheinland-Pfalz and the southern areas of Baden-Württemberg. The headquarter of the French Military Government was in Baden-Baden.

In December 1945 France issued a set of 16 stamps for general use throughout its occupation zone:

 

France also issued occupation postage, semipostal and postal tax stamps for the individual German states that it occupied (southern part of Baden, Rhineland-Palatinate, Saarland and Wuerttemberg-Hohenzollern). Separate French occupation stamp issues generally came to an end in 1949 with the formation of the Federal Republic of Germany. France, however, continued to occupy one German state, Saar, until 1957.

 

Baden

After World War II in 1945, the French military government created the state of Baden with Freiburg im Breisgau as capital out of the southern half of the former Baden. In 1952, Baden was merged with Württemberg-Baden and Württemberg-Hohenzollern to form the new German state of Baden-Württemberg.

 

Rheinland-Pfalz (Rhineland-Palatinate)

Rhineland-Palatinate was created by the French military government as a part of the French Occupation Zone. It comprised lands including the southern part of the Prussian province Rheinprovinz (Rhineland), part of the Prussian province Hessen-Nassau, part of Rheinhessen and the Bavarian Rheinpfalz and consisted in all of 39 counties in 5 districts.

 

Saar

After World War II, the Saarland came under French administration again, as the Saar Protectorate. France attempted to gain economic control of the remaining German industrial areas with large coal and mineral deposits; the Ruhr area and the Saar area (Germany's second largest centre of mining and industry). In 1947, France formally removed Saar from its occupation zone and established it as a French protectorate. Under the French, pro-German parties were banned.
In the Paris Accords of 23 October 1954, France offered to establish an independent "Saarland", under the auspices of the Western European Union, but a referendum held on 23 October 1955 rejected this plan. Instead, the people of the Saar opted for the return of the Saar to the Federal Republic of Germany. On October 27, 1956, the Saar Treaty established that Saarland should be allowed to rejoin West Germany, which it did on January 1, 1957.
The currencies used in the Saar were the Saar mark, introduced in 1947, and the Saar franken, on par with the French franc, introduced in coins in 1954. The German mark was not valid in Saarland until July 6, 1959.

 

A first set of Saar definitives came out in mid-1947, and included 17 stamps using six designs, including worker of various occupations, Mettlach Abbey, and Marshal Ney. Three of these values were also printed on paper watermarked with a pattern of curving lines. These first stamps were denominated in German currency, but just as before, were replaced in November by French currency denominations.
The French established a protectorate in December 1947, and on 1 April 1948 issued a new series inscribed "SAARPOST", followed by another in 1949 inscribed "SAAR". The French issued a few commemoratives each year through 1956, punctuated by a definitive set showing various buildings, in 1952.
The return of the Saar to German control was commemorated on 1 January 1957 by a special stamps, then followed shortly thereafter by definitives with the then-standard profile of President Theodor Heuss, and inscribed both "SAARLAND" and "DEUTSCHE BUNDESPOST". The numerals did not indicate a monetary system, but were implicitly francs; later in 1957, the stamps were reissued with a small "F" after the numeral. Additional commemoratives appeared regularly for several more years while the German monetary was re-established. The last postage stamp of the Saar went on sale 6 May 1959. Thereafter Saarland used the regular stamps of Germany.

 

Wurtemberg