James Ryan has committed to Leinster and Ireland until at least 2023 after signing a new three-year IRFU contract.
The second row has agreed a deal that will run up to the next World Cup in France, where Ryan is expected to be a key man for Ireland - and possibly even the captain.
The 23-year-old has already emerged as one of best players in the world at his position, nailing down a place in the Irish second row in 2017.
Then in 2018, Ryan was part of a team that won a Six Nations Grand Slam, a test series in Australia and secured a win against the All Blacks.
At club level, Ryan has a similarly impressive CV, winning the Champions Cup with Leinster in 2018 as well as claiming back-to-back PRO14 titles in 2018 and 2019.
Ryan was also a member of Ireland's 2019 World Cup squad, where Joe Schmidt's side were eliminated once again at the quarter-final stage.
"I am delighted to sign an IRFU contract," Ryan said.
"A lot has been packed into the start of my professional career with both Ireland and Leinster and there has been some great success and a few disappointments but I am involved in two very exciting squads that want to be challenging for trophies."
IRFU High Performance Director David Nucifora added:
"James is still a young man but he has delivered consistent high-level performances for both Ireland and Leinster. He is growing into a leadership role with the national team and has a big future for both Ireland and Leinster."