Harlequins have signed the Irish international Jeremy Staunton on a two-year contract.
Staunton agreed the two-year deal in a move away from Munster, as has prop Maurice Fitzgerald, who will join from Biarritz.
The club have also added Welsh international, Dafydd James, to their books in another two-year contract.
James, a Test Lion in Australia three years ago, will join Quins from Welsh team, the Celtic Warriors, who are likely to be disbanded by the Welsh Rugby Union in the near future.
James, a wing or centre, missed out on the World Cup last autumn because of injury but Quins feel he still has a lot to offer.
He has won 41 caps, and started all three Tests for the 2001 Lions against Australia, scoring a try during the 29-13 first Test triumph in Brisbane.
Quins, whose Parker Pen Challenge Cup final victory over French club Montferrand last Saturday booked them a place in next season’s Heineken Cup.
And, completing a quartet of new signings, is 22-year-old wing Joe Mbu, who will arrive from Bath.
Quins have also announced the list of players leaving this summer, which in addition to retiring England prop Jason Leonard, features Scott Bemand, Laurent Gomez and Rob Jewell.
Fly-half Paul Burke had already agreed a deal with Munster, as had flanker Pat Sanderson (Worcester) and centre Chris Bell (Leeds).