Why is Germany called Germany instead of Prussia?

You can thank this genius politician for that.

Otto von Bismarck, the founder of Germany. Bismarck was Prussian, he served the Prussian King and build an empire dominated by Prussia.

But the empire and the country that arose from it was called Germany. The reason of this is that Bismarck understood that Prussian was an exclusionary term, and German an inclusive. He did not want an empire that consisted of Prussia and its conquered lands, he wanted a German empire that included Prussia.

For a more etymological explanation. The name Deutschland (German for Germany) comes from diutisc and means “of the people".

In the past German or Deutsch was always used to refere to the people living in the lands. For example “the Holy Roman empire of the German people”, or the phrase “of German blood” from the Dutch anthem. German has also ment “not Latin", which is how the Dutch anthem uses it.

From Quinten Roald Stärk, Studied History at Utrecht University