WHAT makes a good crossword clue?

They must be witty and – above all – fair, says Jonathan Crowther.

And the 73-year-old is speaking from experience.

He has been solving the puzzles since he was a child and, under the pseudonym of Azed, beguiling readers of The Observer with his puzzles for more than 40 years.

From the book-lined study of his North Oxford home, Mr Crowther devises the clues that have appeared every week in the Sunday newspaper since March 1972.

He is only the third person to have held the job and his solvers have included Sir Jeremy Morse – the former chairman of Lloyds Bank and Colin Dexter’s inspiration for Inspector Morse – Mr Dexter himself, the novelist and poet Vikram Seth and the conductor and composer Sir David Willcocks.

He is a good friend of Colin Dexter, who was known for including the names of friends in his Morse stories.

Mr Crowther, who recently passed the milestone of more than 2,250 puzzles, told the Oxford Mail: “There should be fun in crosswords and that is something I’m still anxious to encourage.

“You want people to have that mental challenge and enjoy solving them, because a solver should win.

“The clues must be cryptic, but also witty and accurate.”

Mr Crowther, who grew up in Westmorland, has had a long association with words, but said he still managed to think of original clues.

He studied classics and philology at Corpus Christi College, Cambridge, before joining Oxford University Press in 1964.

After working in India to “learn the ropes from the bottom up”, he returned to the UK to become an editor of dictionaries in London and Oxford.

The father-of-two retired about 12 years ago and lives with his wife Ali.

He first took over as The Observer crossword setter after his predecessor Derrick Macnutt – better known as Ximenes in crossword circles – died in 1971.

“I had discovered his crosswords while at school in Rugby. He was a great pioneer of the cryptic crossword, who brought forward a measure of what was a good clue or a poor clue,” he said.

“When he died I thought ‘what am I going to do with myself on Sundays?’ “Then when I sent off a puzzle of my own to The Observer I had done in his memory they printed it, before sending me a letter asking if I wanted to take over.

“Since then I’ve been doing one a week without a break.”

There was also a competition where readers sent Ximenes clues of their own once a month, a tradition Mr Crowther continues to this day.

His own pseudonym – Azed – follows the tradition of Observer crossword setters taking the names of grand inquisitors of the Spanish Inquisition, masters of torture.

Azed is a reversal of the last name of the inquisitor Diego de Deza.