The 23-year-old hooker, who represented England in a Under 21 World Cup, was one of the bright lights for Swansea, making 21 appearances for the Swans whilst being preferred to Wales international Garin Jenkins in the Celtic League and Heineken Cup last season.
A promising talent, Christian believes that a move back to England and the chance to play in the Zurich Premiership with Bath Rugby was an opportunity too great to miss.
"Bath Rugby is a very good club and I am very happy to be signing for them. I am looking forward to returning to England and competing for a place in the side."
Christian will be battling for his place in the side with Wales international Jonathan Humphreys and Lee Mears and Jack Rowell believes that he is an important acquisition for Bath Rugby as the club continues to develop the squad for next season.
"Christian was first choice hooker at Swansea last season and joins Bath Rugby having gained experience in both the Heineken Cup and Celtic league. At 23 he came recommended to the club as a promising young player of some potential and he is keen to make his way with a Zurich Premiership club.
"Christian is of the same mould as Jonathan Humphreys as he possesses battling qualities and is a tough competitor. A former England under 21 Captain, Christian adds strength-in-depth to the squad and will be vying with the talented Lee Mears to take over Jonathan Humphrey's mantle as first-choice hooker at Bath Rugby."
Christian is the sixth of Bath Rugby's summer signings and will join props Duncan Bell and David Flatman, lock Rob Fidler, scrum half Martyn Wood and centre Andrew Higgins for pre-season training in July.