The eldest son of Prince Charles of Prussia and nephew of the future German emperor William I, Frederick Charles was educated from childhood for a military career. He became a colonel in 1852 and a major general in 1854, in which year he married Princess Marie Anne of Anhalt.

In 1861 he was made a general of cavalry and in 1864 fought capably against Denmark. At Königgrätz on the Bohemian front in the Seven Weeks' War, he commanded the Prussian 1st Army, which had the major responsibility for the decisive victory over Austria.

During the Franco-German War of 1870–71, Frederick Charles commanded the 2nd Army. In the early fighting he drove Marshal A.F. Bazaine's French forces back into Metz, and on Oct. 27, 1870, he received the capitulation of that city. He was promoted to field marshal the following day. Subsequently he captured Orléans, thoroughly disrupted the French Army of the Loire, and broke up Gen. A.E.A. Chanzy's part of that force at Le Mans.

Despite the success of the Metz operations, they were costly in German manpower and were otherwise open to criticism. The Prince's forceful character and tactlessness, moreover, resulted in friction with Gen. K.F. von Steinmetz, commander of the 1st Army, and with Chief of Staff Helmuth von Moltke. Whatever his personal shortcomings, however, Frederick Charles merits recognition as a competent army-level commander.