There is much to interest a lawyer-reader in Elizabeth Foyster’s account of the lunacy commission convened to decide whether the Third Earl of Portsmouth should be declared insane.

Historian Elizabeth Foyster’s subject is the lunacy commission convened to decide whether the Third Earl of Portsmouth, John Charles Wallop, should be declared insane and thereby lose his liberty. Through the commission, instigated by the earl’s own nephew and overseen by the lord chancellor, evidence was heard, mostly in public, of alleged abduction, sodomy, blackmail and domestic violence. On show were developing areas of expert evidence, the treatment of a learning-disabled vulnerable witness (the earl), and contested definitions of ‘lunacy’.

Lawyers feature throughout the earl’s life, including the family’s ‘fixer’, solicitor John Hanson, and Soho advocates who seem to collude in abduction and fraud. Some 800 people crowded the hearings at Holborn’s Freemasons’ Hall, and the press reported all the lurid detail – likely bribing jurors or lawyers to reveal contents of private sessions. The 23-strong jury included MPs and society architect John Soane.

With a shared focus on reconstructing past events with accuracy, the distinct disciplines of law and history heavily overlap – and this commonality has led lawyers to tackle history and historians to tackle legal subjects.

Author: Elizabeth Foyster

£20, Oneworld

Can you spot the difference? I think so. A lawyer might not disagree with a historian’s contention that text (in this case, the available accounts of the trial) cannot be read without context. But Foyster’s interest is two-way – she reads the trial using evidence relating to its context, and seeks to better understand the England of 1823 as reflected in the conduct of, and reaction to, the trial.

For an example of a lawyer’s treatment of a historical event, see Geoffrey Robertson’s similarly excellent Stephen Ward Was Innocent, OK.

Academic historians are cautious about the notion that history contains lessons for or, worse, answers to, modern problems. But while acknowledging that qualification, there is much to interest a lawyer-reader in Foyster’s account.

For example, the debate as to whether ‘support’ for Portsmouth while giving evidence (counsel sat one side of him, a friend the other) would affect his account’s credibility echoes our own discussions on the treatment of witnesses.

Portsmouth was cornered and brought down by this legal process. It was a pitiful sight, and the lord chancellor later reflected that the case had been ‘the most painful business’ of his legal career. Foyster’s account brings that ordeal to life.

Eduardo Reyes is Gazette features editor