England and Harlequins prop Kyle Sinckler has agreed a two-year contract with Bristol Bears.
The 26-year-old British & Irish Lion will switch Premiership clubs in the summer of 2020.
Bristol director of rugby Pat Lam said: "Kyle is an outstanding player and it's fantastic to bring someone of his international calibre to the Bears.
"He's coming into his peak years as a front rower and has a wealth of experience at the very highest level."
Sinckler, who made his professional debut for Quins in September 2011, was a key part of England's 2019 World Cup side, but he only played three minutes of the final against South Africa after being knocked unconscious in a collision with team-mate Maro Itoje.
He impressed throughout the tournament and scored his first international try in the quarter-final victory over Australia.
Sinckler said he could not turn down the opportunity to play under Lam at Bristol.
"The Bears are an ambitious club on the up and it was great to visit the city and the facilities that they have," he added. "There's a clear plan in place for long-term success and I'm looking forward to contributing.
"I'm grateful to Harlequins for everything they have done for me and my career. I'd like to thank the coaches, fans and my team-mates for all their support over the years."