England international Alex Corbisiero is joining the Saints in the summer, while current first teamers Alex Waller and Tom Mercey have both put pen to paper on new contracts to stay at Franklin's Gardens.
Corbisiero, who arrives from London Irish, is regarded as one of the top young props in England. Still just 24 years old, he has racked up 76 first team appearances for the Exiles and 18 England test caps, including in the successful 2011 Six Nations campaign.
Corbisiero - who has played at every age group for his country - was included in England's Six Nations Elite Player Squad last week and the New York-born loosehead says that he is excited by the prospect of joining the Saints.
"I've really enjoyed my time at London Irish and am grateful for everything that the club has given me," he said.
"I'm looking forward to what will be a new challenge at Saints next summer. There is a great culture and hopefully I can help the team succeed whilst continuing my progression as a player, and I'm sure that Franklin's Gardens will be a good environment for me in that regard."
Waller, 22, has become one of the most recognisable names on the Saints team sheet, having been the only player to have featured in every first team matchday squad since the start of the 2011/12 season, something which helped him win the 2012 Saints Young Player of the Season award.
The Kettering-born Senior Academy graduate now has 78 appearances in the black, green and gold under his belt - including the 2011 Heineken Cup final and 2012 LV= Cup final - and says that he is hungry for more.
"It wasn't a hard decision to make," Waller commented. "My family are in the area, I've been playing here for the last four or five years and I feel that I have developed a lot as a player. I want to keep developing and hope that I can do that under the guidance of the coaches and the set-up here at the Saints.
"I'm still learning every game and have played more than I thought I would, especially last season. Hopefully I've become an established member of the squad and can keep on pushing for a starting spot."
Mercey is another prop who is still relatively young despite having amassed considerable experience at first team level in Aviva Premiership Rugby and the Heineken Cup, with nearly a hundred appearances split between the Saints and former club, Saracens and with England Saxons honours under his belt.
Now in his third season at Franklin's Gardens, Mercey says that there is still more to come from the squad.
"The next few years are going to be exciting," he said. "People forget that we're still a young group, and over the next couple of years we'll have the opportunities to step up and show what we can do.
"It was a simple decision to sign again with the Saints. I've really enjoyed my time at the club and all you have to do is look at the quality of player that we have in the squad. But a lot of us are still relatively early in our careers and there is more development and improvement to come, and I'm excited that I'm going to be a part of it."
Director of rugby Jim Mallinder said that the three contracts were important in the development of the Saints squad ahead of next season.
"All three players have plenty of experience and because they are still in their early-to-mid twenties we believe that there is plenty more to come from them," the Saints boss commented. "I'm delighted that all three props have put pen to paper to be a part of the Saints squad going forward."