Paul O'Connell has joined the Ireland senior coaching team as forwards coach.
The former Munster and Ireland second row joins head coach Andy Farrell's set-up, with Simon Easterby switching his focus to defence.
"I am really looking forward to working with Andy and the rest of the coaching group," said O'Connell, who won 108 Ireland caps as a player between 2002 and 2015.
"I worked with Simon as a player and am looking forward to working with him again. It's an exciting young group of players to be involved with and there are talented forwards coming through across the four provinces that will no doubt be pushing for international selection in the coming months and years."
The 41-year-old retired in 2016, before taking on assistant coaching roles with the Ireland Under-20s and Stade Francais - the latter as a forwards coach.
Farrell said that O'Connell will work closely with scrum coach John Fogarty in his new role with Ireland.
"Paul brings a wealth of rugby knowledge with him and as forwards coach he will have responsibility for the forwards including the line-out working alongside John (Fogarty). He will also be another strong voice and leader within the group," said the Ireland head coach.
"Simon (Easterby) has a real passion for defence and having developed Ireland's forward play over the past six years with the additional responsibility for the defence over the past 12 months, he will now be able to focus his energy and rugby intellect on this area of our game.
"The weekend's Interpro games and the European fixtures in the weeks ahead will give players the opportunity to push for selection for the Six Nations squad.
"The squad will not be selected until after the Champions Cup Round 4 fixtures have been completed."
IRFU performance director David Nucifora added: "We have been keen to find the right opportunity for [Paul] within Irish rugby and we think the fit with the national squad will work well.
"He joins the national coaching group with immediate effect as they prepare for the upcoming Guinness Six Nations Championships."
Follow Leinster v Ulster (7.35pm Friday) and Connacht v Munster (7.35pm Saturday) via our live blogs on RTÉ.ie/sport and the RTÉ News app or listen to live commentary on RTÉ Radio 1 Extra and RTÉ Radio 1.
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