Date of birth: 16 Oct 1969
Started training: 1993
Classic wins: 7 (all except 1,000 Guineas)
2002 wins: 10 (UK)
2001 wins: 20 (UK)
2000 wins: 10 (UK)
Despite only being in his early 30s, Aidan O'Brien has already rewritten the trainers' record books.
A successful riding career, capped by his status as Ireland's amateur champion for the 1993/4 season, was cut short at the age of 23 when he opted to apply for a licence.
It was in jump racing that he first made his mark as a trainer, sending out two winners on his first day and breaking prize money records as he won the jumps title in his first season.
He broke the record number of wins for a year in only his second campaign and then decided to try his hand at the Flat.
That opportunity came about when he was asked to take over the famous Ballydoyle stables in County Tipperary, which had previously been the home of racing legend Vincent O'Brien (no relation).
In that year, O'Brien the younger produced a combined total of 176 winners in Flat and National Hunt - a new Irish record until he broke it himself the following year.
The major successes started to come in the 1997 season when he trained the winners of the Irish 1,000 and 2,000 Guineas and the Irish Derby.
The following season, he picked up his first English Classic when King Of Kings won the 2,000 Guineas.
He continued to train jumpers - notably Istabraq, whom he saddled to three Champion Hurdle crowns.
After Istabraq retired in 2002, O'Brien gave up the jumping game but his grip on the Flat was strengthening yet further.
In 2001, his domination stretched across the Irish Sea and he became the first overseas-based trainer since O'Brien Sr to became Britain's leading trainer.
That year he enjoyed unprecedented success, winning 23 Group One races.
They included an Oaks-Derby double with Imagine and Galileo, the latter going on to add victory in the Irish Derby to his CV.
O'Brien also made in-roads in the US, where Johannesburg won the Breeders' Cup juvenile event.
In 2002, O'Brien retained both his English and Irish champion trainer's crowns despite the fact that his yard was hit by a coughing bug during the summer.
That he was top dog in England with just 10 wins - earning £2.8m in prize money - proves the quality of his string.
His successes included Derby winner and runner-up High Chaparral and Hawk Wing, who came home 12 lengths ahead of the field.
Another of his inmates, Rock Of Gibraltar, set a new record of seven consecutive Group One successes.
O'Brien is backed by the Coolmore operation, which undoubtedly gives him a huge advantage.
But his skill at getting his horses to peak at the right time and his attention to detail - a section of the Ballydoyle gallops is modelled on Epsom's famous Tattenham Corner - mean that he currently has no equals in the training game.