Sir Ian Kershaw is a British historian of 20th-century Germany whose work has chiefly focused on the period of the Third Reich. Educated at the University of Liverpool and Merton College, Oxford, Kershaw was originally trained as a medievalist but turned to the study of modern German social history in the 1970s. He is regarded by many as one of the world's leading experts on Adolf Hitler and Nazi Germany, and is particularly noted for his biography of Hitler. He was the leading disciple of the late West German historian Martin Broszat, and professor at the University of Sheffield until his retirement. His wife Dame Betty Kershaw was a Dean at Sheffield.