Taulupe Faletau won his first cap for Wales in 2011
Bath will sign Wales back-rower Taulupe Faletau from Pro12 side Newport Gwent Dragons at the end of the season.
He had been set to join them in October but a move was blocked by Warren Gatland, his national team coach.
The Tonga-born 25-year-old has been capped 52 times by Wales, and represented the British and Irish Lions during the 2013 tour of Australia.
Faletau, who has been with Dragons since 2009, played four times as Wales reached the World Cup quarter-finals.
“The way Bath approach the game suits my style of play,” he said.
“The opportunity to work with Darren (Edwards, Bath first-team coach) again after doing so with Wales Under-20s and the Dragons was also too good to turn down.”
A Dragons statement said: “This comes as extremely disappointing news for the club given our understanding that a national dual contract was being negotiated with the Welsh Rugby Union (WRU).”
Faletau has won two Six Nations titles, including one Grand Slam. A WRU statement said it was committed to keeping its best players in the country when Faletau’s transfer was turned down earlier this year.
However, he will now join the Premiership club once his contract has run out in the summer of 2016, a move head coach Mike Ford described as “evidence” of their ambition.
“When we talk about this club being ambitious, we’re not just paying lip service,” said 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.”