Since the 1950s, Schloss Deichmannsaue in Mehlem has hardly changed from the outside, 2013.
In 1951, a large building complex was added to the castle, 2019.
In 1955, the Allied High Commission announed the repeal of the occupation statute for the Federal Republic in this part of the building, 2019.


US High Commissioner’s headquarters and US Embassy

Deichmannsaue Castle and the buildings subsequently constructed adjacent to it in 1951 were from 1950 to 1955 the headquarters of the US High Commissioner, and subsequently housed the US Embassy. The complex currently houses the Federal Office of Agriculture and Food and the Federal Office for Building and Regional Planning.

Upon the founding of West Germany in 1949, the US High Commissioner was headquartered in a small castle in Bonn-Mehlem. It was at one time owned by the Deichmann family. They were prominent Cologne bankers who, since 1836, had summered in the meadow on the Rhine, where, in 1911, they renovated their estate. Deichmannsaue Castle, after restructuring and renovation measures, later became the headquarters of US High Commissioner John Jay McCloy. In 1951, a modern, 21,000 square meter office building was constructed next to the castle for the staff of the High Commission for Occupied Germany (HICOG).

A special housing tract was also installed in Plittersdorf for HICOG staff and their families. The 1953 edition of Baedeker’s travel guide referred to the tract as “Little America.” The houses were all outfitted with electric cookers, refrigerators, and “hot water available around the clock.” The guide also noted that the tract had its own shopping street, a pavilion-style school, a gym, a swimming pool, a clubhouse, a restaurant and a cinema.

The three-storey Deichmannsaue Castle with its saddle roof and onion dome.
Deichmannsaue Castle became a place of political decisions about the future of Germany, 1949–1955.

The HICOG, however, ceased to function in 1955. As early as May 1952, all three High Commissioners – the American, the British and the French – hammered out the details of a treaty with the German government during a two-day meeting at Deichmannsaue Castle, which was also attended by German Chancellor Konrad Adenauer. The resulting General Treaty (Deutschlandvertrag), which was signed on 26 May 1952 in the parliamentary chamber of the Bundesrat and was a first step toward rescinding the Occupation Statute, came into effect in 1955, by way of the Bonn-Paris conventions. As a result, the office of the Allied High Commission moved from Petersberg to block 3 of the HICOG building in 1952.

Black-and-white photography, view of the well-filled conference room of the former the US High Commissioner’s headquarters
The Allied High Commissioner of France, André François-Poncet, is speaking at the ceremony to repeal the occupation statute on 5 May 1955.

On 5 May 1955 the Allied High Commissioners gathered in one of the new building’s conference rooms. During the following ceremony James B. Conant, the recently appointed US High Commissioner, his French counterpart André François-Poncet and the British High Commissioner Frederick Hoyer Millar signed a document entitled “Proclamation Concerning the Termination of the Occupation Statute and the Dissolution of the Allied High Commission and the Laender Commissions.”

Black and white photograph, a man on a ladder removes the signage at the entrance of the US High Commission.
The end of the Allied High Commission: Changing signs on 5 May 1955.

This proclamation marked the conclusion of the Allied High Commission’s work and made the newly founded Federal Republic of Germany an extensive sovereign nation.

James B. Conant, who had previously served as the president of Harvard University, became the first American ambassador to West Germany, and the Deichmannsaue campus housed the US Embassy from 1955 to 1999.

Black and white photography, a man exchanges the information board of the US-American High Commissariat for one with the imprint "Embassy of the United States of America".
The Allied High Commissioner of France, André François-Poncet, is speaking at the ceremony to repeal the occupation statute on 5 May 1955.

In the summer of 1954, the US Embassy shared the Deichmannsaue facility with the Federal Housing Ministry (among other government agencies), which was housed there beginning in May of 1955. In 2000, the US Embassy moved into its new quarters in Berlin. Since then, the Federal Office for Building and Regional Planning has been headquartered on the former HCOG campus – and since 2005 the Federal Office of Agriculture and Food has also been housed there (it was previously headquartered in Frankfurt).

Did you know...

... that the Soviet Embassy was also located on the banks of the Rhine in Bonn before moving to Viktorshöhe? After diplomatic relations were established between West Germany and the Soviet Union in 1955, the Soviet Embassy was initially housed in the Rolandseck-Groyen hotel in the Rolandswerth district of Remagen – quite a distance from governmental activity.