Why did Germany exclude Austria when it unified?

There are lots of reasons of which the most important are: Bismarck did not technically unify Germany, the states themselves asked to have the King of Prussia as their overlord and Austria did not join in the request. read more

Because Austria almost never was a part of Germany, only during the time from 1938 to 1945, when Germany forced Austria to join the Reich. After 1945 the Allied forces rolled back all the occupations of the 3rd Reich. read more

Austria proposed to unite the German states in a union centered on, and dominated by, the Habsburgs; Prussia, however, hoped to become the central forces in unifying the German states and to exclude Austria out of its affairs. read more