Norman St John-Stevas, a politician noted for his wit, his extravagance and for running afoul of Prime Minister Margaret Thatcher, died March 2 at his home in London. He was 82.

His family announced the death but did not disclose the cause.

Beyond the affectations, which included writing in purple ink and lapsing into Latin, he was a lawyer, an expert on Britain’s unwritten constitution, a former cabinet minister, former chairman of the Royal Fine Art Commission, master of a Cambridge college, and advocate of the canonization of Princess Grace of Monaco.

He was elevated to the House of Lords in 1987, taking the title Lord St John of Fawsley.

“Because I am burdened with a capacity for wit, people have sometimes had the impression that I am not serious in my approach,” he once lamented. “Nothing could be farther from the truth.”

Mr. St John-Stevas first served as a cabinet minister in the waning months of Prime Minister Edward Heath’s administration, and returned after the Conservative victory in 1979 in Thatcher’s first cabinet.

He didn’t last long: He was ejected in 1981 along with other moderate “wets” deemed insufficiently devoted to her policies.

He reportedly referred to Thatcher as “the Leaderene,” “the Blessed Margaret” and “Tina,” the last being an acronym for her slogan “There is no alternative.”

During his time in the cabinet, however, he made a lasting contribution to British governance by reorganizing the select committees in Parliament to review the government’s performance. Those committees are still growing in influence.

Norman Anthony Francis St. John-Stevas was born in London on May 18, 1929. He received a law degree from the University of Cambridge, a master’s degree at the University of Oxford’s Christ Church college and a doctorate at the University of London in 1957. He was president of the Cambridge Union and later secretary of the Oxford Union, the first man to hold office in both debating societies.

He edited the complete works of Walter Bagehot, revered as the greatest expert on the constitution; his own books included “Life, Death and the Law: Law and Christian Morals in England and the United States” (1961), “Agonizing Choice: Birth Control, Religion and the Law” (1971), and “Pope John Paul II: His Travels and Mission” (1982).

Mr. St John-Stevas was elected to the House of Commons in 1964 and remained a member until 1987.

As news of Mr. St John-Stevas’s death spread, his eccentricities were fondly recalled.

David Hughes, chief editorial writer for the Daily Telegraph, said he once went to Mr. St John-Stevas’s home to do an interview, to be greeted by his host in “a full-length velvet dressing gown and a cardinal’s cap.”

Michael Heseltine, who served with Mr. St John-Stevas in Thatcher’s first government, recalled him as “a one-off, a very unusual character.”

“He used to sit at the far end of the cabinet table, and it was quite frequent that there would be an eruption of laughter from that quarter at something he said,” Heseltine recalled. “That used to annoy the prime minister but Norman had the great skill of being able to rephrase a joke to make it sound wholly innocuous.”

— Associated Press