The most successful person in sport in our neck of the woods

Who has been the most successful person, in terms of long term sustained success, in top level sport in the British Isles over the last few decades, if not ever?

There are some small clues in how I phrased the question. The 'most successful person' perhaps implies not necessarily a competitor. So a coach or manager maybe? And the 'British Isles' being the group of islands off the west coast of continental Europe. So including Ireland, then. I realise that particular nomenclature irritates many Irish people but sorry, it's a geographical fact (well, Wikipedia agrees with me) and a useful, if outmoded expression. But it was done not to irritate but to define the question properly and to not completely give the game away, as the person is, indeed, not Sir Alex Ferguson, but Irish.

David Walsh gave me the answer, though he posited it more subtly, by calling horse trainer Aiden O'Brien "the greatest sustainer of success these islands have ever seen". O'Brien was 26 years old and had just 3 years experience of training mostly moderate horses to win mainly jump races, when John Magnier invited him to train horses at his Coolmore stables at Ballydoyle, Tipperary 21 years ago. Aiden O'Brien was the unlikely successor to unrelated namesake Vincent O'Brien, the trainer readers of the Racing Post had voted "the greatest figure in the history of racing". Over a 40 year career Vincent O'B had trained 43 classic winners in Britain and Ireland. The most successful British trainer, Sir Henry Cecil, was some way behind, winning 31 British and Irish classics in a 44 year career. So Aiden O'Brien's appointment might have been considered a gamble, a long odds punt, even a risk. Now he has had the strength of a 200+ team of horses at the modern Ballydoyle behind him. But even so his statistics are remarkable: with his most recent winner, Wings of Eagles at the Derby, Aiden O'B has trained 65 classic winners in 21 years, an average of more than 3 a year and a hit rate he maintained from the off: he won 3 in his first year, starting with a 20-1 shot in the 1997 Irish 2000 Guineas. And Wings of Eagles was a 40-1 outsider, so he doesn't just train favourites. It was his 6th Derby win, including 3 in a row from 2012-14. He's won a lot overseas as well, including 2 Prix de l'Arc de Triomphe. Most of the horses he now trains are sons and daughters of his past champions, from the Coolmore stud machine: he delivers the champion stallions and brood mares, they return him the yearlings.

I'm not an avid horse racing fan, indeed I don't pay it much attention bar a fun day out at the races once a year and watching the Grand National on tv. I didn't see the Derby live. Of course it's a race that often has an exciting finish with jockeys like Lester Piggott bringing a horse late out of the pack and timing their sprint finish. But Wings of Eagles triumph is worth watching on youtube - coming very fast from a long, long way back. A truly remarkable piece of sporting action. And yet another classic for Aiden O'Brien, the most successful person in sport in our part of the world.