THE conquest is complete. A journey that started in the foothills of Crossmaglen 27 months ago has reached the mountain top of a glorious September Sunday in Croke Park.
Donegal are All-Ireland champions for only the second time, while the long wait for those perennial Mayo bridesmaids will now stretch into a 62nd summer.
Did anyone see this coming as the chastened men of Tír Chonaill slinked away from Armagh in June 2010, victims of a nine-point capitulation? Did anyone shout from the rooftops that, with the right manager and rigorous application, Donegal could be champions in the space of two years?
Well, unless you were volunteering for psychiatric committal, we very much doubt it.
On second thoughts, clearly there was one man who believed against all odds and all apparent logic. One man who had the vision to make 'miracles' happen. Jimmy's winning matches, Jimmy's winning games ... Jim McGuinness has also joined the pantheon of great revolutionary managers with the All-Ireland winning habit.
Sport is cruel but no one could deny that the best team yesterday -- and emphatically the best team of 2012 -- have finished with Sam in their lap.
The irony is that Donegal won without quite playing with the same va-va-voom of their earlier landmark victories over Kerry and especially Cork. They didn't have to, however, because coughing up a seven-point lead to Donegal is the equivalent of Gaelic football hara-kiri. That's what happened, courtesy of two goals inside 11 minutes by Michael Murphy and Colm McFadden.
It didn't matter that Mayo 'won' the last hour by three points because they were playing catch-up throughout and never got closer than a goal. There are few teams better at protecting a lead than the two-time Ulster champions and at no stage did you sense that Donegal were about to change that habit on the biggest day of all.
The fact that Mayo were still pushing at the final whistle is a tribute to the resolve that James Horan has instilled in his squad. Would previous Mayo teams have collapsed in the wake of that calamitous double-whammy? Quite likely.
But in the cold light of another All-Ireland final hangover -- the county's sixth in 23 years -- that will be scant consolation to this current team and especially Alan Dillon, who was suffering on-field September heartbreak for the third time.
There are myriad reasons why Mayo came up short once more. Dillon, their string-pulling magician against Down and Dublin, endured a frustratingly peripheral final. Their lack of a killer forward closer to goal (a Murphy or a McFadden) was painfully apparent, as if to underline the loss that was Andy Moran.
Other players who had performed like All Stars all summer -- notably Barry Moran -- couldn't rise to the same rarefied level. Whether that was attributable to their own shortcomings or the more plausible explanation that they hadn't run into a machine like Donegal's beforehand, we'll let you decide. But ultimately, the one over-riding reason for Mayo's latest All-Ireland demise is the most blindingly obvious one. You don't give a team like Donegal a seven-point head start.
Clearly, Donegal must be praised for grabbing the initiative but Mayo were equally complicit in their own downfall.
Murphy's majestic catch and strike will go down as the iconic score of 2012, not to mention Goal of the Season, but that won't stop morose Mayo fans wondering 'what if?' Ger Cafferkey had been handed the man-marking job instead of Kevin Keane.
With the benefit of 20-20 hindsight, it's easy to declare it a match-up blunder but we have some sympathy for Horan's initial decision: Cafferkey had laboured against Murphy when the sides met in the league last March, but he had proven his man-marking credentials all summer against a variety of go-to forwards, and McFadden (far more than Murphy) has been that man for Donegal this season.
As it transpired, though, Keane didn't have the size or strength to handle Murphy when Karl Lacey floated that inviting high ball towards the Hill 16 goal ... and David Clarke didn't even have time to set himself before the ball was flying past his ear.
You could argue that what happened then spooked Keane eight minutes later: as Paddy McBrearty's attempted point rebounded off an upright, the Mayo No 2 was in pole position to clear the danger but, one disastrous fumble later, McFadden had the ball in his hands and then the ball in the net.
Intriguingly, Donegal started like a team intent on going for the early jugular: they started in orthodox fashion with usual sweeper Mark McHugh pushing up on wing-back Lee Keegan, and Murphy hovering around the square. The ploy of bombing direct ball on top of their skipper also struck as a pre-rehearsed tactic. And so, in an uncanny echo of their last All-Ireland final against Kerry six years ago, Mayo had been left shell-shocked by an early two-goal blast.
In fairness to the Connacht champions, that is where the similarities end. They refused to capitulate. Kevin McLoughlin kicked an inspirational opening point and followed up with a second; Michael Conroy kept making runs, kept showing for ball; and when both himself and Enda Varley kicked points from the left wing, the half-time deficit had been cut to 2-4 to 0-7.
And yet, even those last two Mayo scores told a story, for both Conroy and Varley were put under huge pressure by Donegal defenders making desperate attempts to block or hassle the shooter.
Donegal have been doing that throughout McGuinness's tenure, and that incessant pressure eventually has its toll. So it was with Mayo here: with the gap extended to four points, they kicked a necklace of three poor wides via Moran, a Varley free and Conroy.
You could claim, with some justification, that Donegal offered Mayo a potential lifeline with some turnovers and sloppy fouls during the second and third quarters.
Thus, a brace of Mayo frees from Varley and Cillian O'Connor left a goal between the sides entering the fourth quarter. But then Donegal steadied and pushed for home once more, the inspirational Murphy leading the way with some nerveless frees and a fisted point (after outjumping Clarke) that could easily have been a goal.
The rest, as they say, is history.