Vass, 38, played 57 senior games for Saints in two spells and moves back to Northampton after working as defence and skills coach at Montpellier.

His stint in France came after serving as England Under-20 head coach and working as academy coach at Saracens.

"It's great to bring someone of Ian's calibre onboard," Saints director of rugby Chris Boyd told the club website.

"He's passionate about learning and about improving players. I've no doubt he will bring a high level of skill and knowledge to our existing English coaching group."

Vass will take over from Jake Sharp, who served as interim defence coach at Franklin's Gardens after Dickens left to become the new England Under-20 head coach in November 2019.

"I am very excited about the direction in which Saints are heading and where they want to go under Chris Boyd," Vass said.

"This is a massive opportunity for me, and I can't wait to get stuck in."