Bath sign Wales No.8 Faletau
The English Premiership club made the announcement on Wednesday, after being rebuffed in an earlier attempt to sign him.
The 25-year-old, who has played 52 times for Wales and featured in the British and Irish Lions' victorious 2013 tour of Australia, will arrive at the Recreation Ground next season.
"The way Bath approach the game suits my style of play, which was a big factor in me wanting to join," Faletau told Bath's official website, citing the draw of working with Bath first-team coach Darren Edwards.
"The opportunity to work with Darren again after doing so with Wales Under-20 and the Dragons was also too good to turn down. I would like to thank the Dragons for everything they've done for me in my career."
Faletau, who has won three Six Nations titles including two Grand Slams, had been due to join Bath in October, but the move was blocked by Wales head coach Warren Gatland, who wants his players to play in Wales.
"When we talk about this club being ambitious, we are not just paying lip service," said Bath head coach Mike Ford. "Signing a player of Toby's calibre is evidence of that.
"He is a world-class player who never takes a backwards step, and he will add competition to an equally fantastic back row. We are continuing to build a formidable squad that will challenge for silverware for years to come."
Tonga-born Faletau made his Wales debut in 2011 and had been at Dragons since 2009.