Complex sentence: William Raymond Manchester (April 1,1922--June 1,2004) was an American author, biographer, and historian, notable as the bestselling author of 18 books that have been translated into over 20 languages.
Split into simpler sentences: William Raymond Manchester (April 1,1922--June 1,2004) was an American author, biographer, and historian. He was the author of 18 books which been translated into over 20 languages.