Complex sentence: Lynn Townsend White Jr. (April 29,1907--March 30,1987) was a professor of medieval history at Princeton from 1933 to 1937, and at Stanford from 1937 to 1943.
Split into simpler sentences: Lynn Townsend White Jr. (April 29,1907--March 30,1987) was an American historian. He was a professor of medieval history at Princeton from 1933 to 1937, and at Stanford from 1937 to 1943.