Frederick III was German Emperor and King of Prussia for 99 days between March and June 1888, during the Year of the Three Emperors. Known informally as "Fritz", he was the only son of Emperor Wilhelm I and was raised in his family's tradition of military service. Following the unification of Germany in 1871 his father, then King of Prussia, became German Emperor. Upon Wilhelm's death at the age of ninety on 9 March 1888, the thrones passed to Frederick, who had been German Crown Prince for seventeen years and Crown Prince of Prussia for twenty-seven years. Frederick was suffering from cancer of the larynx when he died, aged fifty-six, following unsuccessful medical treatments for his condition.

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.