England locks Maro Itoje and George Kruis have signed new long-term deals with Aviva Premiership leaders Saracens.
The European Champions Cup semi-finalists announced that 21-year-old Itoje and Kruis, 26, will remain at Allianz Park until at least 2019.
The second-row pairing proved an integral part of England's Six Nations side which secured their first Grand Slam since 2003.
In a statement on the club's website, Saracens director of rugby Mark McCall said: "We are extremely happy that Maro and George have committed their futures to the club.
"Both are part of a core group of players who have progressed from the academy to establish themselves as key players within the squad. They have been in superb form this season for both club and country, they are only going to get better and better, and we're excited about them doing it here at Saracens.
"Maro's progress over the last few seasons has been phenomenal. He's experienced a number of big games for the club already, has played for England and is still only 21 years old, which is incredibly exciting.
"In George, we have one of the finest lock forwards around, a player who has shown consistent improvement year on year and still has so much more to come."
Itoje, who made his Saracens debut against Leicester in May 2014, said:"I'm extremely lucky to call Sarries home and I'm delighted to extend my contract for three more years. It was an easy decision from the outset, as I've really enjoyed my rugby so far and I'm incredibly grateful for the help and guidance I have received since arriving at the club as a 14-year-old.
"The club is hugely ambitious and has been competing at the highest level for some time. As a player you want to be playing in the big games, and once again we are well placed in both the Aviva Premiership and European Champions Cup this season. It's a special club to play for and I'm really happy to be staying."
Kruis, who has made 118 appearances for the club since graduating from the academy in 2008, said: "Saracens is a club that is in my heart, and I didn't hesitate to sign a new deal to stay here.
"I owe so much to the club and I am really looking forward to my future at Allianz Park. What's really important to me is that as a young group of players we are all committing our futures to the club together.
"I'm playing alongside my best mates and working alongside them day-in, day-out and that means a lot to me. We've already achieved so much as group of players and there's still so much more to come from us, I'm delighted to be staying here."