Jamie Heaslip admitted he was "humbled" at being asked to lead Ireland for the first time as succession planning for the captaincy began.
With Brian O'Driscoll, Paul O'Connell and Rory Best injured, Heaslip will be in command for Saturday's Guinness Series opener against South Africa at Aviva Stadium (Live on RTÉ Two and www.RTÉ.ie/sport).
Either O'Driscoll and O'Connell, captains of the last two Lions tours, have provided inspirational leadership dating back to 2004, apart from the occasional interruption
But the injury crisis that has decimated Irish ranks has forced coach Declan Kidney to reveal his hand for the future, with Heaslip beating Jonathan Sexton to the honour.
The 28-year-old Lions number eight is unbeaten as a deputising skipper of Leinster and hopes that run continues in an Ireland jersey.
"I was in Baggott Street getting my mate an engagement card when I got the heads up from Declan about it," Heaslip said.
"I was in Tesco and I didn't know what to do with myself. I felt like going out and celebrating. It felt like my first cap again.
"I received a text from (Leinster chief executive) Mick Dawson about my record, so no pressure there!
"It's great. I rang my parents straight away and I'm humbled by the decision. I'm proud to lead this group.
"Once we get on to the pitch everyone will be on automatic pilot because we have such great leaders within the team.
"It's talking after the dinner that's got me more nervous than anything else." - Jamie Heaslip
"It's talking after the dinner that's got me more nervous than anything else."
Kidney revealed that Heaslip has been groomed for the position over the past year.
"We talked with Jamie about the job and he's shown good potential with Leinster," Kidney said.
"Although he'd probably deny it, Jamie is the consummate professional. When he turns up for work he's really zeroed in.
Thanks everyone for your kind words.humbled by it all.it'll be a proud day for me,my family&loved ones.cant wait to wear the shamrock again!— jamie heaslip (@jamieheaslip) November 8, 2012
"That's a good place to start - leading by example. He's been part of this group for a few years now.
"There were other guys holding their hands up for the job but the time is right for Jamie.
"Who should be the next captain has been in my mind for a while. We'd been working on a new leadership group over the past year to make sure that when the day did come, it would be more of a natural progression than a shock to the system."
Hooker Richardt Strauss, born in South Africa but eligible for Ireland on residency grounds, makes his Test debut among an all-Leinster front row of Cian Healy and Mike Ross.
Strauss will lock horns with his cousin Adriaan, who lines up at hooker for the Springboks on Saturday.
Mike McCarthy's strong form for Connacht is rewarded by his inclusion at lock, where a vacancy appeared upon O'Connell's withdrawal with a back problem yesterday.
An inexperienced back row sees Heaslip partner Chris Henry at openside and Peter O'Mahony at blindside.
Simon Zebo makes his first start for Ireland after being capped on the summer tour to New Zealand while Keith Earls replaces O'Driscoll at outside centre.
Uncapped forwards David Kilcoyne, Michael Bent and Iain Henderson are included on the bench.
Apart from O'Connell, O'Driscoll and Best, Ireland are also missing Sean O'Brien, Stephen Ferris and Rob Kearney, leaving a massive void in experience and leadership.
All are Test Lions except O'Brien, Ferris and Best, a trio who are almost certain to be involved in Australia on next year's tour if fit.
"When you lose players of their experience it's always going to be a hurdle to overcome," Kidney said.
"But that's why we've been building a squad over the last couple of years - we always knew this day would come.
"We always hoped it would be drip fed rather than en bloc, but such is the way of things."
Ireland XV to play South Africa: 15 Simon Zebo, 14 Tommy Bowe, 13 Keith Earls, 12 Gordon D'Arcy, 11 Andrew Trimble, 10 Jonathan Sexton, 9 Conor Murray; 1 Cian Healy, 2 Richardt Strauss, 3 Mike Ross, 4 Mike McCarthy, 5 Donnacha Ryan, 6 Peter O'Mahony, 7 Chris Henry 8 Jamie Heaslip.