One of the UK's most beloved cartoonists, Ronald Searle, creator of the tearaway girls' school St Trinian's, has died aged 91, his publisher Penguin has announced.

The artist died on 30 December in a hospital near his home in southern France. "[He] passed away peacefully in his sleep, with his children and grandson by his side," Searle's daughter Kate Searle told Reuters.

Best known for his spiky comic drawings depicting the outrageous antics of the St Trinian's girls, and for his illustrations of the Molesworth series, written by Geoffrey Willans and which, as any fule kno, tells of life at the boys' prep school St Custard's.

Searle "created an alternative to the conformity of Harold Macmillan's Britain", said his publisher Simon Winder. "He gave Britain in the 1950s particularly a sense of anarchy. He was extraordinarily sceptical about all forms of authority [and] there's something just astonishingly anarchic about Molesworth and St Trinian's," said Winder. "That's why they have appealed to so many generations."

Searle began drawing at the age of five. Leaving school at 15, his talent was quickly spotted by the Cambridge Daily News where he worked as a cartoonist, also working for an earlier incarnation of Granta magazine and studying as an art scholar until the war intervened and he enlisted in the Royal Engineers. In 1942 he was captured by the Japanese in Singapore, spending the war as a prisoner at Changi and working on the infamous Burma railway. He recorded his time as a prisoner of war in drawings, preserving them at great risk. His first St Trinian's cartoon was also drawn in Changi.

"I desperately wanted to put down what was happening, because I thought if by any chance there was a record, even if I died, someone might find it and know what went on," Searle told the Guardian's cartoonist Steve Bell, who described the artist as "our greatest living cartoonist, with a lifelong dedication to his craft unequalled by any of his contemporaries", in 2010.

"At times I was so ill that I couldn't draw at all. You're doing 16 hours a day rock breaking and you're exhausted. You come back and have a bowl of rice. You have no light, but you have fire, a big fire keeping the mountain lions away, and snakes perhaps, and by the light of the fire, I made the drawings. I didn't have a watch or anything, so you just lie down in the tent until you were dragged out the next morning to go back to the rock breaking. And so all these drawings, some of them very bad, were all I could do in a state of exhaustion."

His return from the war saw Searle find success with his St Trinian's books, and with the Molesworth series. He moved to France in 1961, and in 2007 the country gave him its highest award, the Legion d'Honneur. His most recent book, Les Très Riches Heures de Mrs Mole, is a collection of the drawings he created for his wife each time she underwent chemotherapy for her breast cancer, "to cheer every dreaded chemotherapy session and evoke the blissful future ahead".