As things turned out, Wimbledon was not the first of the tennis Grand Slams to allow professional players to join in - that honour fell to the French Open at Roland Garros, held earlier in the year from May 27 to June 9.

But the step change that enabled the game to reach its current multi-million dollar standing was precipitated by the All England Club - even if it was the British Hard Court Championships at the sleepy south-coast town of Bournemouth which would prove the unlikely test bed. 

The first serve of the new era was delivered on April 22 at the West Hants Lawn Tennis Club, in front of a crowd of around 100 people.

Much has been made of the spirit of the times in which the move to open tennis was made - as if the authorities were embracing free love and revolution.

We are reminded that the 1960s was the decade when traditional divides were done away with, when black Americans earned significant new social rights as the US Supreme Court, in 1967, invalidated laws prohibiting interracial marriage.

In Europe, 1968 was the year of student and worker activism on the streets, most notably and violently in Paris. 

Indeed, such was the level of civil disorder in the French capital at the time, following a wave of national strikes throughout May, that players involved in that first open Grand Slam were scrambling even to reach Roland Garros.

Nancy Richey, the American player who won the women's singles title, told the New York Times earlier this year: "There were no airlines, the phones didn't call out of the country, the garbage was piled sky high, the gasoline was basically being rationed.

"Everything was basically shut down, and the tournament had official cars and they were having a hard time getting gasoline so they kept asking the players to move closer to the courts. I moved hotels three times."

On May 22, five days before the tournament was to begin, the French Tennis Federation's Organising Committee seriously considered calling it off because of concerns about the lack of public transportation and the financial impact. 

As things turned out, the books were balanced because so many people were free to spectate while they were on strike…

But, while the first open Grand Slam may have been beleaguered by the social shifts of the 1960s, the tipping point towards a sport where the increasingly strained division between professional and amateur players being covertly remunerated was dispensed with appears to have been reached for no other reasons than commercial ones.

The division between gentlemen amateurs and those who were obliged to earn money from sport had existed in numerous sports from the days of Victorian England.

The role of gentleman amateur was given perfect expression in football by Vivian Woodward, who played for Tottenham Hotspur and Chelsea in the years before the First World War without claiming anything more than his bus fare to the ground.

Woodward captained Great Britain to gold medals at the 1908 and 1912 Olympics, and his tally of 29 goals in 23 matches remained a record for England from 1911 until 1958.

An architect by trade, Woodward did not need to earn his living from the game, although that potential alternative was denied him by an injury to his thigh while serving as a captain in the "Footballers' Battalion" during the First World War, after which he took up farming rather than football.

Until the changes that took place 50 years ago, mainstream, that is, Grand Slam, tennis involved amateur players receiving tournament expenses - officially at least - while those who had turned professional hustled and travelled to make a buck.

The first professional tennis tour was organised in 1926, and by the time the 1960s had started a few astute businessmen were beginning to move the sport towards being a domain for professional superstars.

Although professional and amateur tennis players had been unable to play against each other for more than 40 years, by the mid-1960s feeling was rising in the game against "shamateur" tennis - which was characterised by illicit payments.

And Wimbledon was not alone in fearing irrelevance as more talented up-and-coming players made the decision to join the professional ranks, for all the underlying insecurity.

The ATP website reports how the crucial shift occurred in late June 1966, when, during the Wimbledon Championships, the former US world number one Jack Kramer, a leading promoter of professional tennis tours in the 1950s and 1960s, was called to the BBC tent in order to meet the corporation's head of sport Bryan Cowgill and Herman David, the All England Club chairman since 1959.

David was said to have "long become tired of staging 'second-class tennis' and of the clandestine nature of attracting star amateur players to compete at tournaments".

The trio agreed to stage a three-day Wimbledon World Lawn Tennis Professional Championships in 1967, with Kramer supplying eight players - Rod Laver, Ken Rosewall, Pancho Gonzalez, Andres Gimeno, Lew Hoad, Fred Stolle, Dennis Ralston and Earl Buchholz.

The BBC put up prize money of £16,500 ($21,800/€18,500) - worth approximately £283,000 ($374,000/€320,000) in 2018 - for what was planned as a launch to their colour television service on their second channel, BBC Two. The All England Club would undertake the administration and running of the event.

The venture was a huge success, with 14,000 spectators watching Laver beat Rosewall in the final, 6-2, 6-2, 12-10, on Centre Court.

This was the event that convinced David, and thus the All England Club, of what might be achieved in a world of open tennis if they were to allow the Wimbledon Championship due to start in June 1968 free rein.

That said, there were still doubts in some quarters. "Despite the success of the tournament, we still didn't feel open tennis would happen," Laver told the ATP website.

"But it did break the back of amateur tennis.

"When players such as Rosewall, Gonzales and Hoad walked out onto Centre Court, the British public, so keen on tennis and Wimbledon, were so happy that they could watch us play."

The All England Club had been moving steadily towards this position for almost a decade. In December 1959, they called an Extraordinary General Meeting to discuss the issue and a motion had been passed calling upon the British Lawn Tennis Association (LTA) to stage an Open Championship.

The LTA duly proposed the motion at the International Lawn Tennis Federation (ILFT) - now the International Tennis Federation - annual meeting in 1960, where it failed by just five votes to earn the required two-thirds majority.

David declared publicly that amateur tennis had become a "living lie".

Three years later, a further vote was defeated by 49 votes in 1964. And when the British LTA's proposal to introduce a limited number of  Open tournaments in 1968 was defeated by a majority of 56 at the 1967 ILTF meeting, the die was cast.

"It seems we have come to the end of the road constitutionally and that the only way to make the game honest is by unconstitutional action," said David.

On October 5, 1967, an LTA council meeting made public the proposal to delegates that "all reference to amateurs and professionals be deleted from the rules of the LTA, and that the Association itself should legislate only for players," according to Tennis Pictorial International magazine.

Derek Penman, a future chairman of the British LTA in 1970, presented the proposal to "go it alone" on open tournaments starting on April 22, 1968.

On December 14, 1967, at the LTA's annual general meeting - and despite the risk of Britain isolating itself from the international tennis community - the vote for "open" tennis and a welcome to all players at The Wimbledon Championships of 1968 was overwhelming, 295 to five.

It was a business decision.

But as the hugely esteemed writer and broadcaster Bud Collins wrote: "The British weren't so brave or brazen to drop the bomb at the sacred Big W." Instead, one giant leap for tennis-kind would take place at the "Little B".

The Bournemouth final saw Laver, who had been in the professional ranks for six years, defeat fellow Australian Rosewall, who had been lost to the mainstream of the game for 12 years.

Other players had spent even longer as professionals - Gonzalez was in his 19th year of having that status.

There was, inevitably, some awkwardness as the professional and amateurs came together, each having established their own pecking orders.

Several top amateurs, including Arthur Ashe - destined to win Wimbledon in 1975 - and Manuel Santana, Wimbledon winner in 1966, stayed away.

But the amateur cause was effectively championed, to much home celebration, by softly-spoken Cambridge graduate Mark Cox, who beat Gonzalez and then Roy Emerson before Laver stepped in to restore professional pride by beating him in the semi-final.

"Somebody had to be the first to lose to an amateur," the 39-year-old Gonzalez said with a weary smile after his three-hour, five-set defeat.

On the women's side, however, professionals including Billie Jean King, Rosie Casals, Ann Jones, and Françoise Durr boycotted the tournament because the $720 (£545/€615) top prize was so low - and also less than the men's.

Thus began a struggle which would last until 2007, when Wimbledon agreed to offer men and women the same prize money.

Bournemouth was the future. Unlikely, but true. "There's no going back after this," announced Derek Hardwick, head of the British LTA.

So it was onwards to Wimbledon - via the French Open.

By the time the bandwagon reached SW19, the women's professionals had softened their stance over prize money - of which there was a total of £26,150 ($34,500/€29,500) on offer. The winner of the men's title earned £2,000 ($2,600/€2,250) while the women's singles champion received just £750 ($990/€850).

Things have moved on a little since then. In 2017, the total prize money at the Wimbledon Championships was £31.6 million ($41.7 million/€35.6 million) with the gentlemen's and ladies' champions each receiving £2.2 million ($2.9million/€2.5milliion). First round losers received £35,000 ($46,200/€39,500).

Laver, who was just shy of his 30th birthday when he returned to play at Wimbledon, was an extraordinary talent. 

Despite having to miss five years before the game went open, he still amassed 11 Grand Slam singles titles, and became the only player to twice achieve the calendar-year Grand Slam, in 1962 and 1969.

He had first played at Wimbledon as a 17-year-old in 1956. "It was exciting to see Wimbledon, to walk through those gates and be able to get to play on the courts," he said.

Having lost in the first open French Open, where Rosewall beat him in the final, Laver went one better on grass, beating fellow Australian Tony Roche 6-3, 6-4, 6-2 in the final, having defeated the top amateur, Ashe, in the semi-final.

Roche had beaten Rosewall in the fourth round. Santana had returned to the scene of his triumph of two years earlier, but was beaten in the third round by the fast-serving American, Clark Graebner.

King took the first Wimbledon women's title of the open era with a 9-7, 7-5 win over Australia's Judy Tegart, who had beaten Richey in her semi-final. King defeated Jones in her semi.

Laver later reflected that turning professional, when he repeatedly played against the likes of Rosewall, Gonzales and Lew Hoad, had toughened him up.

"I was pretty fortunate this happened for the five years, then when open tennis came along, and I got a chance to play in the open ranks, I was a different player," he told Reuters earlier this year.

"All the amateur guys said 'who is this guy now? He doesn't miss too many, he doesn't make mistakes, his second service is as good as his first'.

"That was the nice thing that happened to me. It (the Open era) was great for tennis."

King said she feels Laver would have won many more Grand Slam crowns had he not been banned alongside the other professionals.

"Here's a guy who missed out on 20 opportunities to win another major, so when somebody looks at his total majors at 11, it's a joke," King told Reuters.

"So when I see Federer win 20, in the back of my mind I wonder how many Rocket (Laver) could have won. 

"There should be a caveat if we're going to do our history right. People sacrificed to try to make the game better."