The event was established in 1834, and it was originally held at
Tempelhof on the site of what became
Berlin Tempelhof Airport. It was initially contested over 2,400 metres, and it was extended to 2,800 metres in 1837. The race was transferred to
Hoppegarten in 1868, and it was cut to 2,200 metres in 1888. It was staged at
Grunewald for a short period after World War I, and it returned to Hoppegarten during the 1920s. It was abandoned in 1945 and 1946, and it moved to Cologne in 1947. The Union-Rennen serves as a trial for the
Deutsches Derby, and many horses have won both races. The first was Schwindler, a joint winner of the Derby in 1875. The most recent was
Sea The Moon in 2014. The 2025 Deutsches Derby winner, Hochkonig, was runner-up in the Union-Rennen. With its running in , the Union-Rennen is Germany's oldest surviving horse race. ==Records==