Along with AJP Taylor, AL Rowse and Hugh Trevor-Roper, Alan, later Lord, Bullock belonged to a generation of historians who were comfortable in academic circles but also adept at popularising their studies.
Lord Bullock: Popular historian
Alan Bullock was born in Bradford on 13 December 1914 and was educated at Bradford Grammar School.
Winning a scholarship to Oxford, he returned there after World War Two - during which he worked for the BBC's European Service - to lecture and went on to become vice-chancellor in 1969.
His best known works were a book on Hitler and a three-volume biography of Ernest Bevin, Foreign Secretary in the post-war Labour government.
But it was his chairmanship of two high-level inquiries which brought him his first taste of national fame, and controversy.
The report on the teaching of reading, A Language for Life, published in 1975, found no evidence of a general decline, but said that a concentrated effort was needed to raise standards.
Alan Bullock (r) on The Brains Trust
It was criticised for complacency.
The 1977 Bullock report on industrial democracy - much leaked in advance - was more controversial.
It proposed the election of worker-directors in companies employing more than 2,000 people.
The CBI did not like it, the unions had reservations, and the Conservatives - then in opposition - rejected it.
While interpreting history is inevitably controversial, and Lord Bullock was a man with ideals, his work was distinguished by its intellectual honesty.
In 1960 he became the first Master of St Catherine's College, Oxford, a post he held for 20 years, and he was vice-chancellor of the university from 1969-73.
Though Lord Bullock naturally felt comfortable in academic circles, he was also adept at popularising history, especially through the mass media.
Lord Bullock said there were times when the historian also had a duty to counter lies, such as the one which asserted there was no Holocaust.
His magisterial Hitler and Stalin: Parallel Lives presented a refreshing and insightful approach to, often overlooked, aspects of the dictators' characters.
Alan Bullock's Hitler and Stalin: Parallel lives was a best seller
Among his other interests, Bullock had been chairman of the trustees of the Tate Gallery and a director of the Observer newspaper.
He was knighted in 1972, and was made a life peer in 1976.
Lord Bullock was a founder member of the SDP, and for a time was party spokesman on education in the Lords.
He was a believer in the nuclear deterrent and also believed that, but for Britain, Stalin would have taken control of much of Western Europe after World War Two.
Alan Bullock regularly appeared on radio and television broadcasts, and was a regular on the radio Brains Trust in the immediate post-war years.
Lord Bullock was married and had five children.