My cousin John Greenacre, who has died aged 85, was a renowned teacher. He was totally committed to Peterhouse school, near Marondera, Zimbabwe, where he recorded 56 years of service. He taught maths and coached tennis and cricket. He also led safaris to the Kalahari desert and Chimanimani national park.

Although John was born in Putney, south-west London, his family had long been based in Durban, South Africa. It was there that his father, Kenneth – an RAF pilot during the second world war – was director of the family department store, Greenacre’s. His mother, Elizabeth (nee Brett), was a devoted wife and mother.

He was educated at Michaelhouse school in Natal, and then Jesus College, Cambridge, where he studied mathematics. He joined Peterhouse in 1959 following an invitation from Fred Snell, a former head teacher at Michaelhouse. Snell’s ambition was to establish a school in Rhodesia, as Zimbabwe was then called, which would reflect the best of British educational traditions.

John was active in helping the development of the school right from the beginning of his time there. He participated in the building of the chapel and, more recently, a magnificent library. John was proud of the school’s unique safari park with its giraffes, zebra, wildebeest and antelopes.

Peterhouse was originally attended by children from the expatriate community, but John encouraged a policy of accepting Zimbabwean pupils. Inevitably, he met with some complaints, but today the school is 90% Zimbabwean.

The vicious guerrilla war of the 1970s affected many in the school, but John remained dedicated to Peterhouse. As a housemaster he often had the difficult task of counselling traumatised pupils.

Robert Mugabe’s government was averse to any form of perceived racism and John’s tact and experience helped to diffuse volatile situations. When a colleague from Britain replaced two Zimbabwean teachers it led to a storm of protest, which reached government levels. John played a discreet role in helping to ease such misunderstandings.

He lived in a small, sparsely furnished bungalow. His extravagance was a glass (or two) of J&B whisky in the evening and an upmarket car – originally an E-Type Jaguar – which delighted the boys and proved useful for visiting his Durban relations.

John is buried in the Peterhouse cemetery. His sister Angela Mai survives him.