Nick Evans, Adam Jones and Jerry Flannery have all signed new coaching deals with Harlequins as the 2021 champions look to "build for the long term".
The extensions to the contracts of Harlequins' three coaches come after a number of players committed their futures to the club.
"Alongside the 17 recent key player contract renewals, we are all thrilled to have Nick, Adam and Jerry commit their futures with us," Laurie Dalrymple, Harlequins' CEO said.
"By signing new and permanent deals within our coaching team working alongside Billy Millard (director of rugby performance) and Charlie Mulchrone (skills and kicking coach] and Tabai Matson (senior coach), we have built a brilliant team to help our squad grow, develop and to achieve our ambitious goals.
"Alongside Billy and Charlie, Nick, Adam and Jerry guided this team to one of the most incredible stories in the Premiership's history [last season].
"Overseeing a return to Harlequins' DNA of old as the team has tapped into the club's historic and famous style of play, we have seen huge engagement and interaction not only from our supporters but the wider sporting world."
Evans is thought by many to have been one of the best overseas signings in Gallagher Premiership history. He guided Quins to their first Premiership title in 2012, after arriving from New Zealand in 2008.
The 41-year-old then made the switch from playing to coaching in 2017 after notching up over 200 appearances and 2,249 points over a nine-year playing career at The Stoop. Evans recommits to the club to extend a 14-year career in London.
Jones extends a seven-year stay with the London side having arrived in 2015 as a player. A year later, his role changed as he took up a joint playing and coaching position, going on to coach full-time after retiring at the end of the 2017-18 season.
Former Ireland international Flannery arrived prior to the 2020-21 season to assume the role of lineout coach, taking on his current title of lineout and defence coach during Quins' spectacular Gallagher Premiership-winning run last year.
"The coaching group did an amazing job last year with a fantastic team," said senior coach Tabai Matson.
"It's always interesting to come from the outside and join a cohesive group - and that's exactly what they were. They are a high-functioning team.
"One thing I've really enjoyed is that they're all completely different.
"They have different energies, they're all fantastic within their portfolios and they all complement each other really well. For me, joining a team like that was exciting. It's fantastic that they've all re-signed as a group.
"What Nick brings to the table is an analytical view. He's got all that experience from his playing days but now he's leading and driving the likes of Marcus (Smith) and Danny (Care). We're blessed to have him in the mix.
"He's completely different to Jerry, who brings this real intensity to the way he leads the lineouts and the defence. He's a fantastic practitioner and I'm not sure if it's just his accent but he's a wonderful storyteller and he drives a lot of the energy in the week.
"And of course, 'Bomb' [Adam Jones], our Welshman. It's really an eclectic group of nations, which is one of the things we love about the game, isn't it?
"Our scrum has often been the thing that's kept us in games, so with his experience and the way he drives the scrummaging, he's been a key part of the success here so far."