Princess Elisa Radziwiłł was a member of Polish nobility, of royal ancestry. She was the desired bride of Prince William of Prussia, who later became William I, German Emperor, but they were not allowed to marry.

William I, or Wilhelm I, was King of Prussia from 1861 and German Emperor from 1871 until his death in 1888. A member of the House of Hohenzollern, he was the first head of state of a united Germany. He was de facto head of state of Prussia from 1858, when he became regent for his brother Frederick William IV. During the reign of his grandson Wilhelm II, he was known as Wilhelm the Great.