Marland Yarde, the England international winger, has signed a two-year contract with Harlequins joining from London Irish.
The 21-year-old will join the London club for the start of pre-season training in July.
Marland was born in Castries, St Lucia, and following his family's move to this country, attended Gunnersbury Boys Catholic School and Whitgift College. He graduated to the London Irish Academy after playing mini and youth rugby at Sunbury-on-Thames with London Irish Amateurs.
He made his competitive senior debut for the Exiles against Sale Sharks in the LV= Cup in November 2010 and has gone on to make 39 appearances during which he has scored 16 tries.
His first appearance for England was at Under 16 level in 2008. He scored five tries in the 2011 Under 20 Six Nations Championship and added two more in the opening match of the 2012 Junior World Championship against Italy. Yarde made his senior international debut against Argentina in June 2013 when he scored two tries.
"Having played all his rugby at London Irish and in speaking to Marland and his mother these past few weeks, I know how much Marland appreciates everything that has been done for him by London Irish. However, once he decided that he wanted to make a change I think we both knew the fit was perfect," said Harlequins director of rugby Conor O'Shea.
"He is young, ambitious, has world class potential and his 'X-Factor' is with ball in hand. We are absolutely determined that we will help him realise his ambitions and look forward to him joining the squad for pre-season training."
"I will always have fond memories of London Irish and can only thank the club for what they have done for me as a player to date and the opportunity they have given me," said Yarde.
"I am excited to move on to the next stage of my career with Harlequins and hope to continue to develop and improve as a player."
Irish admitted they were frustrated to lose the services of Yarde having developed him through their academy, but would move on accordingly.
"We did everything within our power to retain Marland, considering that the club had developed him as a player through our Junior and Senior Academy Programme, progressing to being a valued member of the senior playing squad and ultimate achievement of International Honours," read a club statement.
"An offer of more than substantial new terms was made to Marland so, in the circumstances, the club is disappointed with his decision to move on.
"However, the club must also move on and proceed with our plans to build a team for the future."
"I've been at London Irish since I was 14 years old and have thoroughly enjoyed every moment of it," added Yarde.
"It's easily the hardest decision in my rugby career but I would like to thank everyone at the club who has helped me develop into the player I am today.
"I'd like to thank the supporters for always supporting me and I wish the club all the best for the future."