premise: The first time a single German nation existed was in 1871 when Wilhelm the 1st became Emperor and Bismarck Chancellor. The unified Germany became a great economic and military power, and empire, but defeat in the two World Wars led to its break-up in 1945 into East and West Germany. At that time the Berlin Wall was built and served to separate East from West. In 1990 the wall was demolished and Germany was unified once again.
hypothesis: Germany has been unified as anationon three occasions.