Erich Raeder (1876-1960) was the German supreme naval commander from 1928 to 1943, including much of World War II. The first Grand Admiral since Alfred von Tirpitz, he was also the last.
Raeder joined the imperial fleet in 1894, rapidly rising in rank to Chief of Staff for Franz von Hipper in 1912. He served in this position during World War I as well as in combat posts.
After the war he strongly supported Adolf Hitler's attempt to rebuild the German Navy, while apparently disagreeing equally strongly on most other matters. Raeder also faced constant challenges from Hermann Göring's ongoing quest to build the Luftwaffe.
Nevertheless he was promoted to Grand Admiral in 1939, and later that year suggested the invasions of Denmark and Norway in order to secure sheltered docks out of reach of the Royal Air Force, as well as provide direct exits into the North Sea. These operations were eventually carried out.
A series of failed operations after that point, combined with the outstanding success of the U-boat fleets under the command of Karl Doenitz led to his eventual demotion, and eventually to resignation.
After the war he was sentenced to life imprisonment at the Nuremberg Trials, for waging a "war of aggression". This somewhat dubious sentence was later reduced, and he was released in 1955, later writing an autobiography, Mein Leben.