Conrad Russell, who died Thursday aged 67, held the chair of British history at King’s College, London, from 1990 to 2002 and was a leading revisionist historian of the English Civil War. During the 1990s he became a vocal and effective spokesman for the Liberal Democrats in the House of Lords.

Russell rejected those conventional interpretations of the Civil War that saw it as a clash between theories of the Divine Right of Kings and of parliamentary supremacy. Instead, he saw the conflict in terms of the inherent structural weaknesses of a monarchy whose role included the enforcement of religious conformity, but whose responsibilities extended across three countries – England, Scotland, and Ireland – with very different religious traditions.

The truest predictor to the sides people took in the Civil War, he found, was not people’s views about the constitution, but the attitude people in England took to the Scottish revolt against Charles I’s attempt to enforce observance of the Prayer Book. In Russell’s view, the Civil War could also be seen as a struggle to enforce the hegemony of England within the British Isles, an imperial vision shared by both Charles and Cromwell.

Russell was a flamboyant figure, with a fine head of unruly hair, an ever-present cigarette, and a precise, donnish voice. After taking his seat in the House of Lords in 1988, he made good use of his vast fund of historical knowledge to enliven and illuminate current political issues with recondite references to historical parallels.

He liked to draw a comparison between peerages given to business cronies of political parties and the “the slimy trail of finance” whereby James I sold peerages or gave them to his creditors in lieu of payment.

The following year, after Tony Blair claimed that he never gave money to beggars, Russell suggested in a letter to The Daily Telegraph that, “he should remember that need may happen to anyone. Belisarius in his day was the best general in the Roman Empire, but ended up sitting at the gates of Rome chanting ‘give a ha’ penny to Belisarius.’ If, after Mr Blair has reformed the welfare state and gone out of office at the moment his pension fund goes broke, I find him at King’s Cross chanting ‘give a tenner to Tony’, I will give to him, even if my gorge rises at it.”

Conrad Sebastian Robert Russell was born on April 15, 1937. His father was the philosopher Bertrand Russell (1884-1970); his mother, Marjorie “Peter” Spence, was the philosopher’s pipe-smoking former secretary who be came his third wife in 1936.

The earldom was created in 1861 for Conrad’s great-grandfather, Lord John Russell, twice prime minister and an architect of the 1832 Reform Bill. Bertrand Russell had succeeded as the 3rd Earl Russell in 1931.

Young Conrad spent part of his infancy in America where, before the war, his father had been a visiting fellow at various universities. When he was 15, his parents’ marriage hit the rocks during a holiday in Sicily. A bitter divorce ensued, as a consequence of which Conrad was forbidden by his mother (who obtained custody) from ever seeing his father again. Conrad

Russell’s memory of the split remained raw. Recalling the moment his mother had woken him to tell him a taxi was coming in 10 minutes to take them away from his father for good, he reflected: “I kept thinking that if I had been awake I would have been able to persuade her not to rush out of the door. I have never been able to tackle anything in the first hour after waking up ever since.”

He did not see his father throughout his teens, and was haunted by his mother’s claim that Bertrand Russell was mad and that the illness was hereditary. When, in about 1970, he ended the rift with his father, his mother was so angry that she refused to see her son again. Cruelly, she cut him off just as he was leaving the house for an interview for a fellowship at Oxford. He was not appointed. Russell sometimes said that he felt his family was under a “Greek curse” that caused madness, misery and suicide as well as greatness.

At Merton College, Oxford, he read modern history and involved himself in fashionable left-wing causes, joining the Labour Party in 1956. He was also much admired by women, not only on account of his good looks and romantic radicalism, but also because he led the struggle to admit them into the Oxford Union.

After coming down from Oxford, in 1960 Russell was appointed lecturer in History at Bedford College for Women, part of London University. Two years later he raised a few eyebrows when he married one of his students, Elizabeth Sanders. From then on, however, he listed “uxoriousness” as one of his recreations, between swimming and cricket, and they remained devoted.

At Bedford, he began to publish his ideas on the political history of the Tudor and Stuart periods. His first book, “The Crisis of Parliaments: English History 1509-1660” (1971), was followed by the seminal “Origins of the English Civil War” (1973) and “Parliament and English Politics 1921-1629” (1979). He wrote three further works on the Stuart period: “The Causes of the English Civil War” (1990); “Unrevolutionary England 1603-1642” (1990); and “The Fall of the British Monarchies 1637-1642” (1991).

Throughout his academic career Russell maintained an active involvement in politics, but he became disenchanted with the Labour Party. “The political correctitudes of right and left”, he declared, “I find equally off-putting. They are the enemies of thought.” He took his seat in the House of Lords in 1987, following the death of his half brother, John Conrad Russell, the 4th Earl Russell.

Russell had a reputation for honesty which made all parties happy to deal with him. In 1999 he came in first in his party when the elections to retain hereditary peers were held.

Unlike some Liberal Democrats, Russell had little time for Tony Blair. In 1995, in an article in the Daily Telegraph, he wrote of Mr. Blair: “I will say what Herbert Morrison said when told that Aneurin Bevan was his own worst enemy: ‘Not while I’m around ‘e ain’t’.” Mr. Blair’s policies of aping the Tories, he argued, were fundamentally dishonest: “If Labour have no plans to raise tax at all, they must stop whingeing about social justice.”

Russell’s last book was “An Intelligent Person’s Guide To Liberalism” (1999).