His father, also John Jeffreys (1608–1691), was a Royalist during the English Civil War, but was reconciled to the Commonwealth and served as High Sheriff of Denbighshire in 1655.

During the Popish Plot he was frequently on the bench which condemned numerous innocent men on the perjured evidence of Titus Oates.

Charles II created him a baronet in 1681, and two years later, he was Chief Justice of the King's Bench and a member of the Privy Council.

Jeffreys became Lord Chief Justice in 1683 and presided over the trial of Algernon Sidney, who had been implicated in the Rye House Plot.

John Evelyn, meeting him at a wedding two days later, thought his riotous behaviour unbecoming to his office, especially so soon after Sidney's trial.

Jeffreys conducted the prosecution with far more dignity and restraint than was usual with him, stressing to the jury that they must not convict unless they were certain of Russell's guilt.

A less well-known act of Jeffreys occurred on assize in Bristol in 1685 when he made the mayor of the city, then sitting fully robed beside him on the bench, go into the dock, and fined him £1000 for being a 'kidnapping knave'.

[6] Unable to impose the death penalty, Jeffreys and his colleagues apparently tried to achieve the same result by sentencing Oates to a series of whippings so savage that he might well have died; although, as Kenyon remarks, it was arguably no more than he deserved.

Although Jeffreys has been traditionally accused of vindictiveness and harsh sentencing, none of the convictions has been considered improper, except for that of Alice Lisle tried at Winchester.

Arguably, it was James II's refusal to use the prerogative as much as was customary for the time rather than Jeffreys's actions that made the government's reprisals so savage.

The King's refusal to reprieve her gave rise to a belief that he was taking posthumous revenge on her husband, the regicide Sir John Lisle, who had been one of his own father's judges at his trial in 1649.

Lisle had been murdered by Royalist agents at Lausanne in 1664, but the King had a long memory and may well have felt that Alice should suffer judicial punishment in her husband's place.

As Lord Chancellor, Jeffreys was given the presidency of the Ecclesiastical Commission, a body established by James II under the royal prerogative to control the governance of the Church of England and coerce it.

A story is published, that Jeffreys sought to marry a daughter of a rich City merchant and had a secret correspondence with her, through Sarah, her kinswoman and companion.

Reputedly he was disguised as a sailor, and was recognised by a surviving judicial victim, who claimed he could never forget Jeffreys's countenance, although his ferocious eyebrows had been shaven.

He was first interred privately in the Tower; but three years afterwards, when his memory was something blown over, his friends obtained permission, by a warrant of the queen's[16] dated September 1692, to take his remains under their own care, and he was accordingly reinterred in a vault under the communion table of St Mary, Aldermanbury, 2nd Nov. 1694.

In 1810, during certain repairs, the coffin was uncovered for a time, and the public had sight of the box containing the mortal remains of the feared and hated magistrate.

[17]During the Blitz, St Mary Aldermanbury was gutted by a German air raid and Jeffreys's tomb was destroyed.

The ruins of the church were transported to the United States in 1966 and rebuilt to its original form in Fulton, Missouri, as a memorial to Winston Churchill.

He married Charlotte, a daughter of Philip Herbert, 7th Earl of Pembroke, and Henrietta de Kérouaille, sister of the Duchess of Portsmouth, a mistress of Charles II and a supporter of Jeffreys in the early stages of his career.

[21] After his fall from power, a portrait of Jeffreys was taken from Gray's Inn and left in the cellar of Acton Hall (the family home).