Very rarely in history have people got together because of a common interest in a judge - and when they have it has usually been to conspire to do something nasty to him. Lord Denning is an exception. The social networking site Facebook has a thriving discussion group in his honour that, at the time of writing, has 7,148 members. (The group "Lord Denning is an Arse" has only 41 members.)

The “Lord Denning (M.R.) Appreciation Society” (the “M.R.” stands for Master of the Rolls, an ancient judicial position), explains its devotion to the great judge with a paragraph that begins: “Lord Denning has made countless memorable judgments that have eased the pain of law school readings for millions.” It goes on to say: “While you might not like his reason, you gotta love his rhyme!”

Lord Denning of Whitchurch (1899-1999) was a man of monumental influence over the development of English law, both in its substance and style. Born in the 19th-century, commonly nominated as the most influential judge of the 20th-century, Lord Denning had a substantial impact across many areas of law. Once described as “Ambassador-at-Large for the common law”, he delivered more than 2,000 reported judgments and delivered more lectures and talks than any other judge ever has, nationally and internationally.

Christened Alfred Thompson Denning, known to his friends as Tom, he was a mathematical scholar at Oxford and maths teacher at Winchester before he embarked on a distinguished career as a barrister. During his 38 years in high judicial office - he retired at 83 - he reformed areas of law such as law of contract, unmarried partners and judicial review. By the end of his career, experienced barristers were appearing before him who hadn't been born when he became a judge.

Lord Denning famously often took the side of the socially weaker party against the stronger. He backed deserted wives, wounded soldiers battling the Government over pensions, customers arguing against banks. His strongly argued dissents in the Court of Appeal - where his judgment was outweighed by the opinions of the two other judges with whom he was sitting - were the stuff of legend. In several cases his dissentient opinion even won out, leading to the law being changed in line with his view. This happened in the case of the law of negligence applied to words, under which people can be made liable for their negligent misstatements.

One commonly held assessment of Lord Denning’s jurisprudence (his legal philosophy and approach to law) is that he was more concerned to "do justice according to the parties in a case" than slavishly to follow precedent. His tendency to manufacture new legal principles, or to apply old ones in novel ways, caused consternation among conservative judges. In a family law case from 1953, he said:

“What is the argument on the other side? Only this, that no case has been found in which it has been done before. That argument does not appeal to me in the least. If we never do anything which has not been done before, we shall never get anywhere. The law will stand still while the rest of the world goes on, and that will be bad for both.”

For many lawyers and law students, one of the most memorable things about Lord Denning is the clear, simple, and dry style in which his judgments are written. He was a consummate storyteller. Many of his judgments began in a colourful way. "Broadchalke is one of the most pleasing villages in England," he once opened in a case involving a property dispute between a farmer and a bank. "Old Herbert Bundy was a farmer there. His home was Yew Tree Farm: it went back 300 years . . ."

In another case from 1976, Denning begins "To some this may appear to be a small matter, but to Mr Harry Hook it is very important". Mr Hook, a Barnsley market trader for six years, had his licence revoked by the local council after he had urinated in a side street on an evening when the toilet was shut. He had been confronted by an official. Lord Denning explained:

"We are not told the words used by the security officer. I expect they were in language which street traders understand. Mr Hook made an appropriate reply. Again, we are not told the actual words, but it is not difficult to guess. I expect it was an emphatic version of 'You be off'. At any rate, the security officer described them as words of abuse. Touchstone would say the security officer gave the 'reproof valiant' and Mr Hook gave the 'countercheck quarrelsome' (As You Like It V, iv)"

Lord Denning was a decidedly controversial figure. He sometimes argued in favour of hanging; said that no parent would entrust their child to the care of a female teacher who had slept with her boyfriend; and thought homosexuality should be punished, lamenting that “Hell fire and damnation held no terrors nowadays”. On another occasion he said that if the Birmingham Six had been hanged “we shouldn’t have had all these campaigns to get them released”.

Although he did much good work for African and Asian legal education, he made comments about black people in 1982 that were clearly racist. He said that "black, coloured and brown" people did not have the same standards of conduct as whites. It was that incident, and its condemnation in a leading article in The Times, that triggered his resignation. He did, though, give a public apology for his remarks.

As a passenger in his neighbour’s car one day, Lord Denning was admonished for not wearing a safety belt. "Lord Denning, you know it's the law," his driver advised. With a characteristic chuckle Lord Denning replied: "I am the law". The doctrine of precedent means that, in effect, he still is the law in a great many ways.

Professor Gary Slapper is Director of the Centre for Law at The Open University

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