British historian Sir Martin Gilbert died Tuesday from a 2012 heart arrhythmia from which he never recovered, according to a friend of the family.

Gilbert, 78, was the official biographer of former British prime minister Winston Churchill, and also one of the world’s preeminent Holocaust historians.

Gilbert authored over 80 books, many on Jewish topics, in a life that saw a national service stint in the British Intelligence Corps and a prestigious academic career at institutions including Oxford, where he was an honorary fellow at Merton College. His works included classic histories of the first and second world wars, “A History of the Jews of Europe During the Second World War,” and “Jerusalem in the Twentieth Century.”

Gilbert was made a Commander of the Order of the British Empire in 1990 and received a knighthood in 1995 “for services to British history and international relations.”

A member of the British Iraq Inquiry panel since 2009, Gilbert was described as “an extraordinarily eminent historian” by panel chairman Sir John Chilcot....