The Wrexham-based outfit ended days of speculation when they announced the capture of the 35-year-old full-back or three-quarter, who is the most capped Welsh player of all time, at a press conference at the Racecourse Ground this afternoon.

"I am really excited by the ambition of the Crusaders and playing for someone of the experience and reputation of Brian Noble and Iestyn Harris really excites me," said Thomas.

"This move was not about money but about a chance of a fresh challenge on the field and an opportunity to promote rugby in north Wales off the field."

Thomas won 100 caps for Wales and captained the Lions against New Zealand in 2005 in rugby union.

Crusaders chairman Ian Roberts said: "This is a truly monumental day in the Crusaders' history.

"Getting a player of Gareth Thomas' stature and ability at the Racecourse is a major coup for us. We're building something special here at Wrexham. We want rugby league to succeed in north Wales."

Thomas has signed a contract covering the rest of this season with an option on a second season and will start training immediately under Noble and the rest of the Crusaders coaching staff after being released from contract with Cardiff Blues.

"I think Gareth Thomas is a fabulous player," said Noble. "He's an amazing athlete and I'm a huge fan of his talents.

"He's in fantastic shape and has clearly looked after himself over the years."

Noble does not believe he is taking a risk in signing a player who will turn 36 in July.

"He has all the attributes to succeed in rugby league," added Noble. "He's big and he's strong, has great footwork and he is not afraid to put in a shift in defence either.

"His skill levels are phenomenal and he brings a wealth of experience that you just can't buy. He will add a lot to the team as well as improving the profile of the game here in Wales."

He will start training with his new team-mates on Monday after Cardiff Blues agreed to release him from the two months remaining on his contract, and is expected to make his Engage Super League debut against Catalans Dragons at the Racecourse Ground on March 19.

"I've still got a hunger to play," said Thomas, who has shelved plans to go into coaching.

"I don't want to be sitting in the stand, I want to be out on the field. I don't want to be shouting at someone, I want to be the one to be shouted at.

"That's where my passion lies. I'm as hungry as I was when I was 18.

"I wouldn't expect to come here on a two-year contract. It's new for me and obviously there's going to be some scepticism from both parties, but it's another incentive for me to be successful because I want to be here for two years."

Although he has never played rugby league before, the former Bridgend and Toulouse player admitted he rejected offers from the 13-man game in 1995.

"When I first played for Wales back in 1995, I had a couple of options to go to rugby league then but obviously rugby union was what I cared for at that time," he said.

"I think rugby league has turned into such an amazing sport now. It's a fantastic package that is very desirable for any rugby player of either code.

"I'm raring to go. It was the most exciting option, too exciting to turn down. I think a change is as good as a break. I've had a fantastic rugby union career and achieved a lot.

"Rugby league has always interested me and I'd like to be successful at it. I'd like to look back and say I gave it my best shot."

Thomas, who intends to watch the Crusaders in their next match at Warrington Wolves on Sunday before starting training with them, admits it will take time for him to adjust to the new code.

"I've got to get rid of my instincts as a rugby union player because they won't work as a rugby league player, but that is what the whole challenge is about, being able to adapt myself to becoming a complete rugby player," he said.

"It's going to take time but I'm willing for that challenge. I want to enjoy the game and to be successful."

In December, Thomas openly admitted he was gay, but he does not expect any difficulties in rugby league.

"It's made me into a stronger person," he said of his decision to come out.

"Team people are the same everywhere you go in the world. I feel safe in the team of coaches and team of players that's around me.

"Whatever comes from the outside world comes from the outside world, it's about me being safe and comfortable in my team environment and in the short time I've been here that's the way I feel about it."