As had been widely expected, England forwards coach Steve Borthwick, Ireland defence specialist Andy Farrell and Wales interim head coach Rob Howley will join Lions chief Gatland on the 10-match trip.
Confirmation of the trio came at a press conference in Dublin, with Farrell and Howley returning for another Lions expedition after working with New Zealander Gatland during the successful 2013 Australia tour.
Ex-England captain and current Red Rose forwards coach Borthwick is a Lions newcomer, but he has made a considerable impression during England’s spectacular unbeaten revival under their Australian head coach Eddie Jones.
Former England assistant coach Farrell was appointed as Ireland defence coach earlier this year, and he helped oversee a first away victory over South Africa, followed by a stunning success against world champions New Zealand in Chicago before a memorable autumn campaign which concluded with a win over Australia.
Attack specialist Howley, who is Wales chief while Gatland concentrates on Lions business this season, makes his third successive Lions tour as a coach, while he also travelled as a player in 1997 and 2001.