Leinster and Ireland back-row Sean O'Brien will join Championship leaders London Irish after the Rugby World Cup.
O'Brien has spent over a decade with the European champions, but the British and Irish Lion will link up with the Premiership hopefuls in December.
The flanker, who turns 32 on Thursday, was selected for the Lions tours of Australia and New Zealand and has won 54 caps for Six Nations champions Ireland.
O'Brien, a European Rugby Champions Cup winner on four occasions and two-time Pro14 title champion, is relishing the prospect of playing for Exiles director of rugby Declan Kidney, who handed him a first Ireland cap in 2009.
"After speaking with Declan it was obvious the ambition London Irish have as a club," he said. "I'm keen to roll up the sleeves and use my experience to help re-establish London Irish as a top club in England.
"It's a club that's been around for a long time and there's an obvious connection to Ireland with some greats of Irish rugby having previously worn the jersey. For now my concentration remains solely with Leinster and Ireland but it's an exciting challenge that awaits."
London Irish can confirm the signing of Sean O'Brien, who will join the club in December 2019. Read more https://t.co/ja7NSoJ4eV— London Irish (@LiRFC) February 11, 2019
St Patrick's Party tickets on sale now from https://t.co/MoQMsaijns pic.twitter.com/l7hr7Hvvsd
London Irish are nine points clear at the top of the second tier after being relegated last year and Kidney says the signing of O'Brien shows they mean business.
He stated: "Recruitment is an ongoing process, and we are always on the lookout for players of Sean's ability.
"Sean has proven himself time and time again to be a quality player who sets very high standards for himself and those around him, he leads by example and has a winning mentality.
"We are delighted that Sean wants to come and be a part of our journey as we move back into West London at the new Brentford Community Stadium in August 2020 after he has finished his commitments to Leinster and Ireland at the end of this year."
|Nadal open to grand slam rule changes|
|Jonas Lossl to join Everton on a free|
|Neuer to start for Bayern in DFB-Pokal final|
|Benfica want full €120m release clause for Joao Felix|
|Low welcomes Sane to Bayern rumours|
|Kyrgios withdraws from French Open due to illness|
|Kovac´s Bayern future not in question - Rummenigge|
|Morris not surprised by Lampard´s Chelsea links|
|Reds fall to ruthless Chiefs, Kuridrani stars for Brumbies|
|Villas-Boas expecting Bale to make Premier League return|
|Pique: Anfield opened scars of Rome for Barcelona|
|Osaka wants to channel Melbourne mindset in Paris|
|Cronk´s absence felt as NRL premiers Roosters thrashed by in-form Knights|
|Real Madrid fume at Pochettino´s accommodation joke|
|Halep relaxed ahead of French Open title defence|
|Chiellini would ´hate´ to see former Juventus boss Conte at Inter|
|Oh-no Fernando! Sri Lanka opener taken off on a stretcher following injury|
|A manager of Manchester is coming - Allegri mischievously drops Guardiola hint|
|England captain Morgan sent for x-ray on finger injury|
|Ronaldo is a ´deity´ - Chiellini|
|Should I bet the Eiffel Tower? - Dani Alves confident Neymar will stay at PSG|
|Antetokounmpo insists Bucks are still fighting in Raptors series|
|Wenger: Europa League final being in Baku is ´a nightmare´|
|ATP adds Federer-backed Laver Cup to calendar|
|Aaron Rodgers no match for Packers team-mate Bakhtiari, MLB star Yelich in beer-chugging contest|
|Raptors must live for the moment as NBA Finals beckon, says Leonard|
|Raptors fan Drake: I love this team and we´re going to the NBA Finals|
|Copa del Rey final: Valencia can see a bright future after 11 years in the shadows|
|Majestic Messi, Bale´s bliss, Sevilla slaughtered – Barcelona´s five successive Copa del Rey finals|
|He´s a winner - Mourinho has no doubts over Cech´s commitment amid Chelsea links|
|French Open 2019: The top Opta facts ahead of Roland Garros|
|DFB-Pokal final 2019: Are RB Leipzig the new pretenders to Bayern Munich´s throne?|
|French Open 2019: Djokovic has an opportunity to come full circle at Roland Garros|
|Another Champions League final loss would be hard on Klopp – Mourinho|
|Antetokounmpo hurt his ankle late in Game 5, says Budenholzer|
|Jets´ Darnold ´really pumped about´ playing with Bell|
|Three takeaways from Raptors´ Game 5 road win over Bucks|
|Raptors take series lead over Bucks after come-from-behind win|
|Lippi named China coach again|
|Polanco proving his worth as Twins keep rolling|
|Archer will be England´s ´X-factor´, says Kohli|
|Inglis enters facility for treatment of mental health issues|
|Wenger plans football return, unsure about role|
|Griezmann can decide if he wants Atletico farewell – Cerezo|
|Finau leads at Colonial, Spieth starts well|
|Drake, Spike Lee and Rihanna – five times celebrities became part of the game|
|Molinari pleased to be in the mix at Made in Denmark|
|This Week in US Sports: Durant not cleared, Stanton suffers setback|
|With him, we managed to win – Pjanic congratulates departing Allegri|
|Klay Thompson fumes at All-NBA snub|
|Last-gasp goal sets up Canada´s overtime triumph|
|Aggressive Zverev into Geneva semis|
|Union Berlin hold Stuttgart in relegation play-off first leg|
|Durant, Cousins set to feature ´at some point´ in NBA Finals|
|Sabalenka, Garcia battle through in Strasbourg|
|It is time to step aside – Julio Baptista announces retirement|
|Giannis, Harden unanimous selections in All-NBA First Team|
|Mercedes dominance makes F1 more boring - Scheckter|
|Manchester United to play Solskjaer´s hometown club in friendly match|
|Nadal and Federer in same half of French Open draw|
|I´m the reserve tank for the boys – ´Calmer´ Klopp still ready to provide a spark|
|Kompany won Anderlecht job after six-hour meeting with Arnesen|
|Osaka and Serena set for French Open quarters clash|
|Bale backed by just nine per cent of Real Madrid fans|
|Lauda got successful Ferrari doing the right things - Scheckter|
|Polanc storms into Giro ascendancy after breakthrough Benedetti win|
|Man City star Sane is a Bayern target – Hoeness|
|UEFA dismisses Montenegro appeal against stadium ban|
|Woods to play Memorial ahead of U.S. Open|
|Joao Felix picked by Portugal as injured Andre Silva misses out|