(CNN) -- Ireland's Paul O'Connell will captain the British Lions for their 10-match tour of South Africa starting at the end of May, coach Ian McGeechan announced on Tuesday.
O'Connell was an integral part of Ireland's Triple Crown and Grand Slam triumph.
The giant lock forward got the nod over his own national captain Brian O'Driscoll, who led Ireland to an historic grand slam earlier this season.
O'Driscoll had been widely expected to land the prestigious job, but McGeechan opted for the combative second row forward.
O'Connell will lead a 37-strong squad containing only two Scots for a tour that includes three Tests and was described by McGeechan as "the ultimate challenge for any rugby player."
Munster star O'Connell will follow in the footsteps of England's Martin Johnson who was selected to captain the 1997 Lions on their winning trip to South Africa despite not being his national skipper at the time.
The inspirational O'Connell is in the same mould as Johnson, who went on to captain England to World Cup triumph in 2003.
He has led Ireland on four occasions, each time standing in for O'Driscoll, and also skippered provincial side Munster to the European Cup last year.
"It's a massive honor," the 29-year-old told Sky Sports News, revealing that he had kept the news secret for over a week.
"Brian (O'Driscoll) gave me a ring the other day after we had spoken to Ian and was great about it.
"The main thing will be leaning on the experience of the coaches and leaders within the squad."
O'Connell's cause was further helped by the omission of three national captains Ryan Jones of Wales, Steve Borthwick of England and Scotland's Mike Blair from the squad.
Months of speculation ended as Lions manager Gerald Davies revealed the party which is chosen from the home nations of England, Wales, Scotland and Ireland.
Other notable omissions included Wasps fly-half Danny Cipriani and injury-hit Jonny Wilkinson and Gavin Henson with the biggest surprise the exclusion of England flanker Tom Croft who was rated a likely member of the starting XV.
Fourteen members of the squad come from the all-conquering Irish team with no less than eight from Munster, 13 are from Wales, eight from England with Ryan Hines and Euan Murray the lone Scots.
"Naturally there were some tough decisions and there will be disappointed players but I am confident that this is a very strong and capable squad," said McGeechan.
"Its composition reflects the form shown in the Six Nations and domestic rugby and has a balanced blend of experience and youth."
The Lions will leave for Johannesburg on May 24 ahead of a three-Test series against world champions South Africa, which begins in Durban on June 20.
British and Irish Lions squad:
Full-back: Lee Byrne (Wales), Rob Kearney (Ireland) Wing: Shane Williams (Wales), Leigh Halfpenny (Wales), Ugo Monye (England), Luke Fitzgerald (Ireland), Tommy Bowe (Ireland) Centre: Tom Shanklin (Wales), Jamie Roberts (Wales), Brian O'Driscoll (Ireland), Keith Earls (Ireland), Riki Flutey (England) Fly-half: Ronan O'Gara (Ireland), Stephen Jones (Wales) Scrum-half: Mike Phillips (Wales), Harry Ellis (England), Tomas O'Leary (Ireland) Number eight: Jamie Heaslip (Ireland), Andy Powell (Wales) Flanker: David Wallace (Ireland), Stephen Ferris (Ireland), Alan Quinlan (Ireland), Joe Worsley (England), Martyn Williams (Wales) Lock: Alun-Wyn Jones (Wales), Paul O'Connell (Ireland, capt), Donncha O'Callaghan (Ireland), Simon Shaw (England), Nathan Hines (Scotland) Prop: Gethin Jenkins (Wales), Adam Jones (Wales), Andrew Sheridan (England), Phil Vickery (England), Euan Murray (Scotland) Hooker: Jerry Flannery (Ireland), Lee Mears (England), Matthew Rees (Wales)