Leinster will be chasing a third European crown in the space of four seasons when the race to reach Twickenham kicks off with the reigning champions travelling to face tournament new boys Montpellier in Pool 2.
The Irish provinces have scooped five titles in 16 years, and reached two other finals, and their numbers will be swelled to four for the first time this season with Connacht joining Munster, Ulster and the reigning champions among the 24 elite teams.
Connacht's John Muldoon and Eric Elwood joined the other provinces' captains and coaches at the launch on the banks of the River Liffey.
Back rower Muldoon said: "Obviously we are very excited to be here. We've been a long time knocking at the door but it's great to be competing now at Heineken Cup level.
"Just looking down at our pool, it doesn't get any easier the more you look at it. It's going to be a big challenge. It's one we're really looking forward to and we can't wait to get stuck into the pool matches.
"Everyone in Connacht, we know we're going to have to step it up over the next few weeks - we've got a lot of tough games coming up.
"This is where we want to be. We've been wishing to be in this competition for a long time, we're here now and we've got to back it up and show that we deserve to be in it."
Click here to view the provinces' pool fixtures for the 2011/12 Heineken Cup.