Ulster and Ireland captain Rory Best will retire from professional rugby after this year's Rugby World Cup.
Best's contract expires after the tournament in Japan, and the 36-year-old says the time is right to "go out on his own terms".
The veteran hooker has won 116 international caps for his country, and was named captain in 2016. Best - who is currently out of action due to an ankle injury - has won four Six Nations titles and two Grand Slams.
Best scored 10 tries for Ireland, and captained Joe Schmidt's men to an historic victory over New Zealand in 2016.
The Craigavon native started his career with Banbridge RFC, and also represented Portadown College and Belfast Harlequins RFC.
He made his Ulster debut in 2004, racking up 219 appearances for the province, scoring 23 tries.
Best, who was also included in the British & Irish Lions squad in both 2013 and 2017, says he has "mixed feelings" about his retirement.
"It is with mixed feelings that I announce my retirement from Ulster as of the end of this season," Best said today.
"This feels like the right time for me to go out on my terms, a luxury for which I feel very privileged.
"I am very excited for the end of the season with Ulster and for the upcoming World Cup with Ireland, both of which I hope to finish with a massive high, playing at the top of my game.
"In my 15 years at this brilliant club, I have been lucky to have met, played alongside, been coached by and supported by many great people, and I would like to thank every individual for the time they have invested in me since 2004.
"I grew up supporting Ulster, have been fortunate to play and captain Ulster, and now look forward to supporting Ulster in the future with my family."