The Lions, in their various guises, have travelled on 11 occasions to play New Zealand since 1904 but only once, in 1971, have they managed to win a series.
In that period they have tasted victory in a grand total of six of the 38 tests - with three draws.
On their last visit in 2005, with a squad brim-full of English World Cup winners and coached by Clive Woodward, they were hammered 3-0.
This time the Lions will face an even more formidable New Zealand team, back-to-back world champions who have been the game's totally dominant force for the past eight years.
Two of the three tests will take place at Auckland's Eden Park, where the hosts have not lost a match since the sport turned professional in 1995 - 36 successive victories, with the vast majority against the best of the rest in the form of South Africa and Australia.
As if that was not hard enough, the Lions have been presented with an almost laughably difficult build-up.
They kick off with the only easy-looking fixture of the 10-match tour, against Provincial Barbarians on June 3.
But even that comes just one week after the English Premiership and Pro-12 finals, which could involve the best part of half of Gatland's squad.
With barely a chance to get to know their room mates, the squad will then take on the Blues, followed by the Crusaders, the Highlanders and the Chiefs - all teams packed with quality who are currently tearing up the southern hemisphere's Super Rugby competition.
NEW COMBINATIONS
Long gone are the days of a few easy warm-ups for the coaches to have a leisurely look at new combinations.
By the time of the first test on June 24 the tourists will feel as if they have played half a dozen games of virtual international intensity.
Coming off the back of a never-ending domestic season, they will have suffered further injuries and many of the coaching teams' best-laid plans will have been torn up.
With all that against them, they then face arguably the greatest team in the history of the sport at a fortress where the Lions have won once in more than a century of trying.
"This is the toughest tour," said Gatland, who as a New Zealand native knows the terrain as well as anyone.
"In previous tours the midweek games tended to be a little easier, but when you look at the quality of the opposition we're facing in midweek, it's going to be hugely challenging."
Sam Warburton, who will captain the Lions for the second time, was also fully aware of the scale of the task ahead.
"If someone says 'what do we have to do well to beat the All Blacks?', it's everything," he said.
"I don't think there's an aspect of the game, whether it's scrum, line-out, kicking game, contact area, tactically - you have to be on the money pretty much every game.
"Every player from 1-23 has to contribute massively in every test match to be able to get the win."
But Gatland, having led the Lions to a 2-1 series victory over Australia four years ago, believes the squad will travel with real belief.
"I don’t think we should get on the plane unless we think we've got a chance of beating the All Blacks," he said.
(Editing by Ed Osmond)
