Every four years, something special happens in rugby union as the four home nations unite and their best players combine as the British and Irish Lions.
The earliest tour was held in 1888 and, while the demands of the professional game mean the trips have been reduced and now feature only three Tests, those matches are often some of the best in those 48 months.
In fact, one former Australian star was recently reported to have said that the 2013 series felt more significant than the 2015 World Cup final.
With the Wallabies the opponents again in 2025, here's a look back at the greatest Lions trips.
Still the only time the Lions have won a Test series against New Zealand, Welsh coach Carwyn James led a trip that started with a defeat in Australia to Queensland and spanned three months and 26 games, the last being a final Test draw at Eden Park to secure a 2-1 series victory.
Against an All Black side featuring Laurine Mains, Sid Going, Colin Meads and others, James moulded a team featuring JPR Williams, Mike Gibson, Barry John and Gareth Edwards behind a scrum featuring fearsome lock Willie John McBride among others.
Other parties have come close in the 'Land of the Long White Cloud', but the 1971 side remains the only one to achieve this feat of sporting immortality.
Several of the winners against the Kiwis did it again three years later, on a controversial trip to South Africa due to the country's political situation.
This time 'only' 19 matches long, the Lions won the four-Test series 3-0, drawing the last game 13-13 when they had a legitimate Fergus Slattery try ruled out and the referee called time four minutes early, suggesting a tie would be better for his personal safety.
That summed up the tour. While Syd Millar's tourists played some brilliant rugby on the firm grounds of their host country, it was also a bruising affair that prompted the infamous "99" call.
Captain McBride had observed that provincial players were targeting some of his colleagues to intimidate and potentially injure them ahead of the Test series.
With "999" deemed too slow to shout, the camp settled on "99", which would be bellowed if a player felt victimised and promoted a "one in, all in" mentality in which his teammates would set about their closest opponent.
It was supposedly only used once but the Lions' collective response showed they meant business.
The first tour of the professional era was always going to take some navigating, especially with the Lions taking on the world champions,
In 1995, South Africa captain Francois Pienaar was famously handed the Webb Ellis Trophy by President Nelson Mandela in one of the Rainbow Nation's greatest unifying moments.
Pienaar was one of the players to have departed, but the Springboks were arguably stronger two years later. However, while their elite had found a new level, their gnarled provincial players had retained their physical edge.
Violence again plagued the tour, but magical moments also highlighted it. Bok captain Gary Teichmann may still be looking for the ball after Matt Dawson's outrageous try-scoring dummy in the first Test, while Jeremy Guscott's poise to drop an unlikely goal settled the second match and gave the tourists an unassailable advantage.
South Africa won the final Test to settle the series 2-1, but it remains one of the great trips, with coach Ian McGeechan's candour and, most famously, his assistant Jim Telfer's hair-raising 'Everest' speech immortalised in the iconic 'Living with Lions' documentary.
Another 2-1 win, this time in Australia, but crucially the Lions' first victory since 1997.
McGeechan's side were unlucky four years earlier against another world champion Bok outfit but the 2013 trip Down Under presented a chance. However, a Wallabies side supposedly in the doldrums showed up and levelled the series in the second Test.
Coach Warren Gatland had been hampered by injuries, with captain Sam Warburton sidelined for the decisive Test, but demonstrated his ruthlessness by dropping Brian O'Driscoll for the final match in Sydney and selecting 10 Welsh players.
The gamble paid off as the tourists cruised home 41-16.
It wasn't the best rugby, or against the best opponent, but the 2013 tour rejuvenated the Lions concept, showing that even on a truncated trip, there is still time to bring the best players together and form a side that can better a rugby superpower.
The biggest missed opportunity of the professional era? Gatland's preference for a limited gameplan meant that despite scoring one of the greatest tries ever, his side was second-best in the opening Test of the 2017 tour of New Zealand.
His response was to cruelly drop captain Peter O'Mahony, recall the fit-again Warburton and bring another of the heroes of 2103, Johnny Sexton, into the back-line.
Sonny Bill Williams' early red card in the second match in Wellington helped, but for those watching there was an intangible feeling that the Lions were simultaneously starting to click and working the All Blacks out. Finally, they were whipping the ball wide with pace and got their reward at the 'Cake Tin'.
The decider was a cagey affair as Gatland's team repeatedly came from behind and there was late controversy when, with the scores tied at 15-all following Owen Farrell's 77th penalty, referee Romain Poite overturned a kickable penalty after an accidental offside by Ken Owens.
Not for the first time, New Zealand chose not to attempt a drop goal and the game and the series ended in a draw.
The Kiwis, who were double world champions, had lost some key figures since their 2015 global triumph, but still boasted all the Barrett brothers, Sams Cane and Whitelock, and captain Kieran Read.
However, considering the form at the time and pedigree of the Lions' matchday 23 for the final Test, it is hard to argue against it being the greatest of the modern era.