It was the highest international score of his career, but it was also a performance destined to reverberate politically for the next 22 years.

Most felt that it had assured him of selection for the England squad for the winter series in South Africa.

D'Oliveira, South African born, had been barred from playing Test cricket for his homeland because of his ethnicity.

South Africa was in the grip of the system of strict segregation known as apartheid. Under this, D'Oliveira was classified as "Cape Coloured".

It was later revealed that, at some stage after D'Oliveira's innings, Surrey County Cricket Club secretary Geoffrey Howard had received a telephone call. At the other end was a South African voice warning that if D'Oliveira was included in the English team, then the tour would be off.

In the immediate aftermath of the innings, veteran cricket writer E.W Swanton wrote prophetically in the Daily Telegraph of "the possibility which would seem to exist that D'Oliveira's fine innings may imperil the tour to South Africa".

In those days, the squads for overseas tours made by England were chosen by the influential Marylebone Cricket Club (MCC). Chairman of selectors Doug Insole and England captain Colin Cowdrey were joined by a Committee packed with members of the cricket establishment for a meeting which lasted almost six hours.

The minutes of the meeting are apparently nowhere to be found. In 2004, journalist Peter Oborne re-examined the affair for his award winning book D'Oliveira - Cricket and Conspiracy. He wrote: "Even 35 years on, it is impossible to obtain the full story. Far more is known about the cabinet meetings of Harold Wilson, or the activities of the secret service in Moscow, or the details of the Poseidon nuclear missile programme."

When the squad was announced there was no place for D'Oliveira.

Many believed that the decision to omit him was politically motivated. They accused club treasurer Gubby (Later Sir George) Allen and Arthur Gilligan, a former Sussex and England captain, of being friendly to the South African regime in Pretoria. They pointed to Gilligan's pre-war connections with a British fascist organisation.

When Insole faced the press as chairman of the selection panel, he told them "in the side we have selected, we have got various players who are rather better".

All D'Oliveira would say at the time was "I am bitterly disappointed".

D'Oliveira had become a popular figure since arriving in England in the early 1960s. He had made rapid progress and had been chosen for the first time by England in 1966.

When news filtered through of his omission from the tour party, some MCC members called a special general meeting and condemned their Committee's "mishandling of affairs".

This protest group were soon joined by the Reverend David Sheppard, a former England Test batsman and a vehement opponent of the apartheid regime who later became Bishop of Liverpool.

They called for no future internationals to be played against South Africa until "evidence can be given of actual progress towards non-racial cricket".

There was then an incident which changed everything.

Warwickshire bowler Tom Cartwright had originally been selected but there were doubts about his fitness.

"The injury to Cartwright has not responded to treatment in the way that had been hoped," selectors said. "Basil D'Oliveira is being invited to join the touring party."

It later became clear that D'Oliveira had rejected a lucrative offer from the South African Sports Foundation to coach that winter. It was conditional on his non-availability for England.

In London, Parliament had been informed of the British Government's position by Sports Minister Denis Howell. "The MCC have informed the Government that the team to tour South Africa will be chosen on merit and any pre-conditions the host country lay down will be completely disregarded," he said.

"If any player chosen were to be rejected by the host country, there would be no question that the projected tour would be abandoned."

Next came the response of South African Premier John Vorster at a gathering in the Afrikaner heartland of Bloemfontein.

"It is not the MCC team," he said. "It is the team of the anti-apartheid movement. We are not prepared to accept a team thrust upon us. It is a team of political opponents of South Africa."

Shortly afterwards, it was announced that the tour was off, although calls for the resignation of senior MCC figures continued.

Vorster's statement came at a time when South Africa's position in world sport and the Olympic Movement was becoming increasingly isolated. They had not taken part in the Olympics since 1960 but even so had not yet been expelled.

International Olympic Committee (IOC) President Avery Brundage was determined to keep the door open and had dispatched a Commission to the Republic. This was comprised of vice president Lord Killanin, an Irishman, Reg Alexander from Kenya and the Nigerian Sir Adetokunbo Ademola. 

The terms of reference seemed deliberately muted. Before they set off, Brundage wrote to Killanin and said "if we are to judge apartheid per se, it is not for us to send a Commission at all".

During their time in the Republic, the trio met Prime Minister Vorster, Olympic officials and representatives of the anti-apartheid movement.

They were also invited to see a rugby match at Newlands. Ademola took his place in the Presidential box, a privilege denied to many ordinary citizens of South Africa who shared his ethnicity.

Although Killanin described the atmosphere as "eerie", his Commission concluded that the South African National Olympic Committee should be allowed to send a team to the Mexico City 1968 Games provided that it was open to all.

Brundage insisted: "We have not accepted South Africa - we have merely invited a multi-racial team."

Although Brundage saw this as a victory for the Olympic Movement, most others recognised that it would have been a largely cosmetic exercise.

There came the threat of a boycott, not just from other African nations, but from the Caribbean, the Islamic world and the Soviet bloc. This prompted the IOC Executive Board to recommend to its members that it would be "most unwise for a South African team to participate".

For all that, it was not until two years later that the IOC voted to definitively exclude South Africa from the Olympic Movement.

The sporting world continued to suffer the threat of boycott as non-Olympic sports such as rugby union maintained its links with the Republic throughout the 1970s and early 1980s. In late 1969 the South African Springboks began a tour of Britain. And despite what had happened in 1968, a South African cricket tour was also planned for the English summer of 1970.

"Stop the 70 Tour" was founded as a protest group. A young South African activist, Peter Hain, was at its head. The subject was also discussed at the Cambridge Union, the debating chamber of the University.

The newly constituted Test and County Cricket Board set up a special Committee "to discuss all aspects of the tour, including ground protection". The names of members were kept secret.

Barbed wire was installed at Lord's Cricket Ground in London. Organisers tore up the original schedule and the tour was reduced from four months to 11 weeks. All matches would be played on the larger grounds where security could more easily be arranged.

British Prime Minister Prime Minister Harold Wilson called the tour "a big mistake" in a television broadcast and India threatened to boycott the 1970 Commonwealth Games due to be held in Edinburgh. Sir Alexander Ross, chairman of the British Commonwealth Games Federation, added his voice to calls for cancellation.

Finally, in mid-May, the British home secretary Jim Callaghan called on the cricket authorities to cancel the tour. Instead, an alternative series was arranged at very short notice. England included D'Oliveira who proved one of their success stories with a century and nine wickets against the Rest of the World. 

The visitors included South African stars Eddie Barlow, Barry Richards, Mike Procter and the Pollock brothers, playing alongside West Indians, Pakistanis, Indians and an Australian in an all-star multi-national side which was the very antithesis of apartheid.

Though unofficial rebel tours were arranged, South African teams never played official international cricket again until after the release of Nelson Mandela.

An official New Zealand rugby tour to South Africa in 1976 triggered a boycott of the Montreal Olympics. The selection of South African born runner Zola Budd and swimmer Annette Cowley for the 1986 Commonwealth Games prompted another boycott as many countries accused Britain of disregarding the 1977 Gleneagles Agreement, signed to discourage sporting contact with South Africa. 

In 1994, the South Africans played a Test match at Lord's for the first time in 29 years. Present as an honoured guest was D'Oliveira. He had played a unique part in galvanising sporting opposition to the apartheid regime.