Ireland and Lions lock Jeremy Davidson is returning to play for his home province Ulster next season.

The 26-year-old will rejoin the Irish provincial side from French club Castres after touring Australia with the British and Irish Lions over the summer.

Davidson left his first club Dungannon to join London Irish five years ago, before moving to France in 1999, after Castres had offered him a contract while he was out of action with a cruciate ligament injury.

Weeks of speculation about his future ended with Davidson concluding negotiations with the Ulster branch amid rumours of a fall-out with Castres over his forthcoming international commitments.

Castres have already qualified for the Heineken Cup next season - in which Ulster will also play - by winning their division of the French Championship, but are still involved in the play-offs which which begin next weekend at the quarter-final stage.

Davidson, who has captained Castres for two years, is required for Lions duty at the same time, however. And there was also the likelihood that Davidson would be unavailable for 11 weekends next season due to Ireland's busy international calendar.

"My commitments with the Lions caused a few problems with Castres so the time was right to come back to Ravenhill," Davidson said.

"It was always my intention to return and after negotiations with the Ulster Branch a deal was struck."

The signing leaves only Keith Wood, Kevin Maggs and Geordan Murphy among the current Ireland squad playing abroad - a result of the concerted efforts by the Irish Rugby Football Union to centrally contract home-based players.

It has been reported that Davidson almost chose to go to Munster rather than Ulster.

The reigning Inter-provincial champions have a vacancy to fill in the second row after the departure of popular Wallaby John Langford.

Davidson was approached by Munster coach Declan Kidney earlier in the season during an Ireland squad session in Limerick, and they were said to be in touch again this week.

"I had thought about playing for Munster - they are a good side," Davidson added. "But I am happy to be coming home. I had been thinking about it for a while."

Ulster team manager Joe Miles said: "It's a tremendous boost for the squad. There was a lot of hard talking done, but in the end Jeremy could not look any further than Ulster.

"A lot of credit must go to assistant coach Mark McCall, who did a lot of the ground work in the absence of Alan Solomons to bring Jeremy home."