Relations between the two countries date back to World War II during which time Germany supported the independent Croatian state NDH, which had broken off from Yugoslavia. The former supported the plans of the latter to engage in a sustained persecution of non-Croat peoples (Jews, Serbs, and Roma). 
Germany has to date had close co-operations with Croatia. When Croatia declared independence on 25 June 1991, many German politicians and other leaders declared support, with then German Foreign Minister Hans-Dietrich Genscher being one of the strongest advocates of international recognition of the newly freed country, as well as Slovenia, which declared independence a few hours later on the same day. Then-Chancellor Helmut Kohl (CDU/CSU) was also a vocal supporter of the cause as were many German, Austrian, Hungarian and Italian politicians, church leaders and others.