[1] Russell became a historian working on the origins of the English Civil War and critical of older Whig and Marxist interpretations.

Russell argued that the Civil War was much less a result of long term constitutional conflicts than had previously been thought, e.g. by Lawrence Stone and Christopher Hill, and that its origins are to be sought rather in the years immediately preceding the outbreak of war in 1642 and in the context of the problems of the multiple kingdoms of the British Isles, a hypothesis for which he was indebted to the pioneering study of Helmut Koenigsberger.

This area is still being explored by historians like John Adamson and David Scott even if their detailed conclusions vary from those reached by Russell.

[3] Russell's health worsened in the late 1990s and in 2004 he died of respiratory failure and the complications of emphysema, at Central Middlesex Hospital,[4] a year after the death of his wife in 2003.

He notes (p. 24) that his father's career is a reminder that a free society is not a guarantee against losing an academic job for holding very unpopular opinions on non-academic subjects, as Bertrand Russell in fact did twice.