In 1862, he became prime minister of Prussia. Prussia was then one of 39 weak German states. Bismarck wanted to unite all the states into one strong nation. He organized 22 states into the North German Confederation, in 1867, with Prussia as leader.
To unite the rest of Germany, Bismarck steered Prussia into three wars. First, Prussia fought with Austria against Denmark. Then Prussia turned against and defeated Austria. Prussia's war with France, from 1870 to 1871, established the German Empire. The German states not in the confederation helped Prussia win, then found themselves part of the empire.
Wilhelm I became emperor. But Bismarck became chancellor (chief minister of state) and had all the power. He ruled for 19 years, and was called the "iron chancellor," because he allowed no one to disagree with him, and because he said that only "iron and blood' could unite Germany. In 1888, Wilhelm II became emperor. He was jealous of Bismarck's power, which he wanted for himself. So he forced Bismarck to retire in 1890.
