Gloucester have announced that Sir Ian McGeechan is to work with the club in "an advisory capacity".
McGeechan, who was knighted in the most recent New Year honours list, was Lions head coach in 1989, 1993, 1997 and 2009 and took charge of the midweek side in New Zealand in 2005. He has also coached Scotland, Northampton and Wasps. As a player he represented Scotland 32 times and toured with the Lions in 1974 and 1977.
Gloucester's head coach, Bryan Redpath, said: "I've known Geech for many years now and his record speaks for itself. In this game, you can't afford to stand still, you need to keep looking for ways to improve things.
"He is unique in the game of rugby union and the opportunity to work with him and benefit from his knowledge and experience is fantastic."
McGeechan said: "It's a terrific challenge. Gloucester as a club really do have so much potential. I think, as is shown by recent results, that things are certainly moving in the right direction under Bryan and the rest of the coaching staff.
"It's a great club, a real rugby club with a great stadium and tremendously loyal supporters. My job now is to work with Bryan with the aim of helping Gloucester take the next step and realise their massive potential.
"I'm very excited to be involved. I've already been around the training ground and met everyone and can't wait to get started."
Gloucester are ninth in the Guinness Premiership, 16 points off a play-off place. Having failed to qualify for the Heineken Cup quarter-finals, they will play Wasps in the last eight of the Amlin Challenge Cup in April.
They have qualified for the semi-finals of the LV Cup. They will face the Cardiff Blues (the holders and the side to whom they lost in last year's final), on Sunday 14 March.