Ireland star seeks greener pastures
"Obviously we are disappointed with the ultimate outcome of our negotiations with Robbie, however, we respect the decision he has made and wish him all the best with the Irish team into the future," said Connacht head coach Pat Lam.
Speaking about his decision to move, Robbie Henshaw admitted: "I would like to thank everyone involved in Connacht Rugby who has played a part in getting me to where I am today, from my club Buccaneers, to my school Marist College and all of the coaching staff in Connacht Rugby itself.
"I was fortunate to be given my chance to play pro rugby at just 19 years of age and it's been an incredible journey over the past four seasons, culminating in my breakthrough onto the national team.
"I also want to thank the Connacht fans who have always been so supportive of not just me but the team as a whole.
"Connacht are sitting in a strong position both in the Pro and Challenge Cup and I am determined to play my part to ensure we finish the season out on a high."