The German Empire was founded through the unification of Germany in 1871. The German Empire was made of 26 constituent territories, with each being ruled locally by various royal families. The Empire was made of four kingdoms, six grand duchies, five duchies, seven principalities, three free Hanseatic cities, and a single Imperial territory.
They were part of the "Triple Alliance" or "Central Powers", made principally of the Austro-Hungarian Empire, the German Empire, and the Ottoman Empire, with additional member Bulgaria. They were in opposition against the "Triple Entente" or "Allied Powers", made principally of the Russian Empire, France, the United Kingdom, the Kingdom of Italy, the Empire of Japan, and the United States of America.