Munster lock Paul O'Connell will lead Ireland in Saturday's RBS Six Nations opener against France in Paris.
Munster's Paul O'Connell will lead Ireland for the first time
The 24-year-old forward will fill the role vacated by Brian O'Driscoll, who has a hamstring injury.
"Paul is full of fire and enthusiasm and the perfect man to get a team going," said coach Eddie O'Sullivan.
Ireland have made four changes from the team that lost to France in the World Cup, bringing in Gordon D'Arcy, Tyrone Howe, Anthony Foley and Shane Byrne.
The choice of O'Connell, who will be winning only his 16th cap, may be viewed as a surprise, but the Limerick-born forward is considered to be a star in the making.
He made a try-scoring debut against Wales in the 2002 Six Nations before injury curtailed his immediate rise in stature until the World Cup in Australia.
An athletic line-out exponent, he led from the front in every game and was chosen by many in the final World XV.
Coach Eddie O'Sullivan said he was in no doubt who should captain the side when O'Driscoll was finally forced to pull out late last night with a hamstring injury.
''Paul's on fire at the present time, and playing out of his skin,'' O'Sullivan told BBC Sport. ''There is no doubt he's the talisman in the pack, and that is what we need.
''Not only that, he handles himself extremely well. It's a big call, and it will be his biggest challenge so far.''
Meanwhile, D'Arcy, the Leinster utility back, will fill in for O'Driscoll in midfield, partnering Kevin Maggs.
D'Arcy, has been a revelation this season for Leinster and looks set to make an impact again on the international stage.
He first came to prominence as a teenager in the 1999 World Cup when he made the first of his five Ireland appearances against Romania.
He dropped out of the limelight a few seasons later, made a comeback in the friendly against Wales last August, but failed to make the World Cup squad.
Howe, meanwhile, has bounced back into the frame after a fine season with Ulster.
Ronan O'Gara gets the vote over David Humphreys
The 33-year-old winger looked to have ended his career following the 2001 Lions tour to Australia.
However, the Ulsterman, who will win his 11th cap, has impressed with a number of tries this season in Europe and the Celtic League.
Munster veteran Anthony Foley returns at number eight after he was forced to sit out the game in Australia through injury.
The only other change is the expected elevation of Leinster hooker Shane Bryne in place of the retired Keith Wood.
Ronan O'Gara gets the nod at fly-half ahead of favourite David Humphreys, who has been having problems with a shoulder injury.
''It's a problem to chose at times, but one that I can live with,'' O'Sullivan said. ''It could have gone either way again, but O'Gara just gets in with his present form.''
Ireland: G Dempsey; S Horgan; K Maggs; G D'Arcy, T Howe; R O'Gara, P Stringer; R Corrigan, S Byrne, J Hayes, M O'Kelly, P O'Connell, capt, S Easterby, K Gleeson, A Foley.
Replacements: F Sheahan, S Best, D O'Callaghan, V Costello, G Easterby, D Humphreys, A Horgan.