But while that star trio now share a special link to the life of our most recent King, one particular Lion can claim a far closer relationship with Queen Elizabeth II's father.
Louis Greig toured South Africa with the Lions in 1903, playing 17 games for the tourists and featuring in all three Tests, but it is his life off the field that deserves special attention.
Greig enjoyed a remarkable relationship with the rich and famous, with his correspondents ranging from senior political figures such as American President Dwight Eisenhower and British Prime Minister Ramsay MacDonald to film stars like John Wain and Johnny Weissmuller, the actor who first brought Tarzan to life on the Hollywood screen.
That list in itself is enough to conjure up thoughts of a life lived in incredible circles but it pales into insignificance when compared to the times he shared with royalty.
Born in 1880 to a Scottish merchant father in a comfortable house in Glasgow, Greig would go on to become one of the most trusted voices in the inner circles of the Royal Family.
His calming influence on the young Prince Albert, who would later become King George VI, was such that the pair would later be nicknamed 'King and Tonic'. His standing among the royals is further emphasised by the fact that Queen Mary, the wife of King George VI, was named his son's godmother, while George VI was godfather to one of Greig's two daughters.
Greig's relationship with the Royals was one built on personality rather than privilege and one that can even claim to have rugby imbedded in its beginnings.
Famed for his foul mouth on the rugby field, it was claimed that some spectators would turn up to games to hear Greig swear rather than watch him play! Greig once dropped a ball in front of King George V and, being aware of who was within earshot, had apparently said: ''Oh b . . . other" and been met with a bemused stare from the King.
Greig's relationship with King George VI actually began when the Scotland captain, who was a doctor in the Royal Navy, treated the then 13-year-old Prince for flu and whooping cough when he was a naval cadet on the Isle of Wight.
King George V was immediately drawn to Greig's down-to-earth manner and straightforward approach that was in stark contrast to the simple 'yes, Your Majesty' attitude adopted by most members of the Royal court.
Greig made such an impression that George V ensured that he and the young Prince served on the same ships, with Greig given responsibility to look after Albert during his time at sea.
The young Prince and his mentor forged a close relationship despite their 15-year age difference, with their friendship growing right up until Greig was captured by the Germans during the First World War. Royal records show that immediately after he arrived back in the UK following his release, Greig was summoned to Buckingham Palace. George V saw just two people that day: the Secretary of State for War, Lord Kitchener, and Greig.
William isn't the only Prince to be associated with a Lion
The next chapter in Greig's relationship with the Royals was even more remarkable. Queen Mary herself believed that if it were not for Greig's intervention, Prince Albert would never have lived to become King George VI.
The Prince suffered with an undiagnosed illness during Greig's time as a prisoner of war and George V and Queen Mary asked for his medical opinion. Greig told them he would opt for an investigative operation if he were his son and the Royal pair took his advice without question.
The operation showed that the Prince had a duodenal ulcer, for which he received treatment and then fully recovered. Greig was rewarded with the status of Commander of the Victorian Order for his services to the Royal Family but perhaps even more satisfying was the fact that Mary regarded him as the man who had saved her son's life. From this point on, it is perhaps hardly surprisingly that Greig became an even more integral part of Royal Life.
Described by many as 'The Man who made the King', Greig became a permanent fixture in Prince Albert's journey into adulthood. He played a key role in looking after the Prince, helping him gain confidence in society and even aiding him in his courting of his future wife, the woman we know as the late Queen Mother.
When Albert studied at Cambridge University, the King insisted Greig rent a house (paid for by the Royals) in which he would live with the Prince and his brother Henry. And when Albert eventually left the Royal Navy for the Royal Air Force, Greig went with him, learning to fly at 40 years of age and being credited with guiding the Prince in his own flying lessons.
Greig even played doubles with Albert at the Wimbledon Tennis Championships in 1926, a feat seemingly unthinkable in today's modern age, although that momentous occasion happened after Greig had been forced to take a step back from Royal affairs after his relationship with the Prince cooled.
And although the friendship between Greig and King George VI was never as strong after the death of George V, Greig's efforts in helping turn a Prince into a King should never be forgotten.
While in the film it is speech therapist Lionel Logue who is credited for ensuring Albert becomes more comfortable in his public position after his brother Edward VII abdicates the throne, it is surely Greig who must be equally highly praised for his more long-term role in the development of one of our country's most-respected leaders.
Greig's Lions low down
Date of birth: November 17,1880
Date of death: March 1, 1953
International career: captain of Scotland, 5 caps
Lions Tour: South Africa, 1903
Lions Tests: 3
Lions debut: versus Port Elizabeth July 18, 1903
Last Lions appearance: versus South Africa September 12, 1903
Life among leaders
As well as his remarkable life with the Royals, Greig was very close to two Prime Minsiters in Ramsay MacDonald and Winston Churchill.
Knighted by MacDonald for political services, Greig was personal air secretary to Churchill in the Whitehall war bunker during the Second World War.
He went on to become chairman of the All-England Tennis Club and has been credited with the idea of bringing in the ballboys from Barnados.
Greig was chairman of the Not-Forgotten Association and was also a governor of Westminster Hospital and Guy's Hospital.