Heinrich Brussow will join Northampton Saints in January once his commitments to Japanese club Docomo Red Hurricanes end.
Capped 23 times by South Africa, flanker Brussow shot to prominence when he shone during the 2009 Lions tour, causing chaos as he helped the Springboks to a 2-1 series victory.
After spending five seasons in Japan, Brussow has decided that the time is right for a new challenge.
"I feel humbled to be afforded the opportunity to join a club with such a rich history and traditions," said Brussow of his new side. "Franklin's Gardens is one of those special places you hear some of the best players in the world talk about and the thought of representing a team like Northampton Saints is something that excites me immensely.
"I am looking forward to learning from new coaches, team mates and getting know and experience everything Northampton has to offer. The reputation of the Saints as a team speaks for itself and I want to play my best possible rugby and hopefully contribute to winning a few trophies."
After losing Louis Picamoles to Montpellier in the summer, the Saints had been on the look out for someone to fill the void left by the Frenchman's departure, and the club's director of rugby Jim Mallinder is delighted to have secured Brussow's signature.
"Heinrich has shown his class year in, year out, and we're delighted that he has decided to join us," Mallinder said. "He has plenty of experience and our younger players will learn a lot from him, especially from his play at the breakdown."