Complex sentence: He became President of the Royal Naval College Greenwich in 1946, Commander-in-Chief for the Far East Station in 1949 and Commander-in-Chief, Allied Forces Northern Europe in 1951; he retired in 1953.
Split into simpler sentences: He became President of the Royal Naval College Greenwich in 1946 and then Commander-in-Chief for the Far East Station in 1949. He was made Commander-in-Chief, Allied Forces Northern Europe in 1951; he retired in 1953.