The King's school in Ely stopped playing rugby because of declining interest, compared to football and hockey, and increasing fears of litigation over injuries.
But Susan Freestone, the first female head of the 1,000-year-old school, has reinstated the game after a vote of parents and pupils.
The move, within weeks of her becoming head of the school where annual fees top pound;18,660, was backed by 90 per cent of parents, 88 per cent of senior boys and 78 per cent of juniors.
"If you take something away, so many people want it. It's human nature," Mrs Freestone said.
She does not think rugby's reputation as a brutal game was deserved.
"I like rugby because it's a game for all shapes and sizes, not just for big beefy boys," she said. "It's also for tall, willowy ones, and the small, quick ones can be fly-halves. There is a lot more incentive for co-operation and teamwork in rugby."