They were together for 16 years at Munster, winning two Heineken Cups as the province's half-back pair. They made their Ireland debut together and went on to play at international level for more than a decade, winning the Grand Slam in 2009.
As a combo, Peter Stringer and Ronan O'Gara are inextricably linked.
It's nearly three years since ROG kicked a ball in anger but the career of his former teammate marches on.
At 38, Stringer is still playing. Currently, he's with Sale Sharks - and will be next season too. In February, the Premiership side announced the evergreen scrum-half had signed a new contract.
— Sale Sharks 🦈 (@SaleSharksRugby) February 26, 2016
The link between Stringer and O'Gara got even closer on Friday night.
Stringer lined out for Sale as they fell to Top 14 high-flyers Montpellier in the quarter-final of the Challenge Cup. This appearance for the Corkman was one of remarkable note. It was his 112th game of European rugby, equalling the number set by his long-time friend and teammate O'Gara. The two now jointly hold the record for most appearances in European rugby.
Given Stringer's incredible longevity and his signing of a new contract with Sale, 112 is surely a number we will see him pass next season.
Picture credit: Stephen McCarthy / SPORTSFILE