Frankie Dettori has been appointed as retained rider by Sheikh Joaan al Thani, the Qatar-based racehorse owner.
The three-time champion jockey split with the powerful Godolphin team, owned by Dubai's ruler Sheikh Mohammed, in October 2012 after 18 years.
Dettori, 41, had been riding as a freelance following his return from a six-month drugs ban on 31 May.
He said: "I'm thrilled to have taken a job for an outstanding new owner. I'm looking forward to the association."
Sheikh Joaan's Al Shaqab Racing is considered one of the growing forces in international horse racing.
The brother of the Emir of Qatar's horses include the talented Craven Stakes winner Toronado, who has been ridden in all six of his previous races by current champion jockey Richard Hughes and is trained by Richard Hannon.
Hannon said he expected Hughes to keep the ride when Toronado faces a rematch with his 2,000 Guineas and St James's Palace Stakes conqueror Dawn Approach at Glorious Goodwood.
"We have been told that Hughesie rides Toronado in the Sussex Stakes at Goodwood, which is great news, and I am pleased with the arrangement," said the trainer.
Al Thani, who also has the Marco Botti-trained Planteur in his British-based team, owns the Haras de Bouquetot stud farm in Normandy.
He also recently bought Naas Listed winner Sandiva, who Dettori partnered when second in the Albany Stakes at Royal Ascot.