Top Irish jockey Ruby Walsh and leading English trainer Paul Nicholls are to end one of jump racing's most successful partnerships.
Walsh, 34, is to concentrate on riding for another employer, Irish champion trainer Willie Mullins.
Walsh, who has two young daughters, has cited regular travelling to the UK as a reason for the split.
He partnered horses such as Kauto Star, Denman and Big Buck's during a decade riding for Nicholls.
Somerset-based Nicholls has said that Walsh will still ride for him "when he is needed and when he is available".
Walsh/Nicholls big-race wins
- Queen Mother Champion Chase, 2004:
- King George VI Chase, 2006, '07, '08 '09 & '11:
- Cheltenham Gold Cup, 2007 & '09:
- Queen Mother Champion Chase, 2008 & '09:
- World Hurdle, 2009, '10, '11 & '12:
He was on board Kauto Star for his record-breaking
five King George VI Chase wins,
and two victories in the Cheltenham Gold Cup in 2007 and 2009.
Nicholls was champion trainer for seven years running until Nicky Henderson won the title last season.
Daryl Jacob, who is currently second jockey to Nicholls and
won the 2012 Grand National
on Neptune Collonges, will step up as Walsh's replacement.
Walsh said Nicholls has been "responsible for some of the most amazing days of my life".
the Irish Examiner
: "I started as Paul's stable jockey in October 2002, but when I chose to live in Ireland, this was always going to be a job that involved a lot of travelling.
"Paul has never been anything but fair and honest since our association began and has been responsible for some of the most amazing days of my life.
"From King Georges and Tingle Creeks, to Champion Chases, World Hurdles and Gold Cups, he has been behind them all.
News of the Nicholls/Walsh split not only propels Daryl Jacob, 29, into the no 1 spot, but also a strong position to challenge for the jump jockeys' title in the future.
Unlike his predecessor, who based himself in Ireland and was shared by Nicholls with Willie Mullins - Walsh called it "the best of both worlds" - Jacob lives locally and has no other big employer.
The 2012 Grand National winner will ride the majority of horses at Nicholls HQ, from where way over 100 winners (155 once) have been produced for each of the last 12 seasons.
That's sure to make Jacob a formidable opponent.
"Being stable jockey there enabled me to ride in, and win, the biggest races in our sport, so walking away from my position as stable jockey was never going to be easy.
"However, I felt towards the end of last season that the travelling was starting to take its toll - my family and I were like passing ships in the night."
paid tribute to Walsh,
who has ridden more than 700 career winners in Britain as well as over 1,400 in Ireland.
"Myself and Ruby have been chatting for the past couple of months. It was clear that the constant travelling to and from Ireland, with his wife Gillian and the girls at home, was becoming a bit of a grind for him," Nicholls said in his
"It would have been exhausting for someone young and single, let alone a grey and ageing family man!
"But he was getting up before 5am, and not getting home until after 8pm, when riding over here - before his girls got up in the morning, and after they went to bed most nights - and when you have a young family that must really take its toll.
"He came over to explain his decision on Saturday, and we both agreed it was the best way forward in the circumstances.
"Ruby had a difficult and unenviable job trying to satisfy both myself and Willie Mullins down the years, so at least that's another weight off his mind, as well as the travelling."