Rowntree was part of the successful Lions tour to South Africa in 1997
England coach Graham Rowntree is to join the British and Irish Lions for the 2009 tour to South Africa.
The 37-year-old was named scrummaging coach by Martin Johnson in August and has now been recruited to fill the same role by Lions head coach Ian McGeechan.
He is the final part of the Lions coaching team for the 10-match tour, which begins in Rustenburg on 30 May.
"It is a tremendous honour to be asked to become involved with Geech's coaching set-up," said Rowntree.
The former Leicester prop, who won more than 50 England caps, was a playing member of McGeechan's successful Lions squad which toured South Africa in 1997.
He also featured in two Tests during the 2005 tour to New Zealand - when the hosts completed a 3-0 clean sweep - and made 12 Lions appearances in total.
"Having experienced both the highs and lows of Lions rugby as a player, I am determined to be part of a winning set-up in 2009 and relishing the opportunity to work with the other coaches to make that happen," said Rowntree.
McGeechan, who had previously named Wales trio Warren Gatland, Rob Howley and Shaun Edwards in his backroom team, said Rowntree understood "the Lions ethos" and what they were trying to achieve as a coaching group.
"The scrum will be an intensely contested area in South Africa and we'll need to be technically accurate at scrum time from the moment we arrive," said McGeechan.
"It is crucial to have a forward pack that are technically as good as they can be against a renowned set of South African forwards."
England team manager Johnson backed Rowntree's appointment, even though it means he will miss England's summer tour to Argentina as a result.
"Having played alongside Graham for many years at club and international level, and having seen him coach the England squad, I know what an asset he will be to the British and Irish Lions," he said.
"I will give due consideration to replacing Graham for the tour to Argentina."
The 2009 Lions tour features three Tests against world champions South Africa, with the first against the Springboks set to take place in Durban on 20 June.