Former England centre Luther Burrell has signed a two-year contract with Newcastle as the Falcons prepare for their return to the Premiership.
The 32-year-old is returning to union after leaving rugby league side Warrington Wolves earlier this month.
The 2020-21 Premiership season is scheduled to begin on 20 November.
"He's in fantastic shape and it's great we have been able to secure his signature," said Falcons director of rugby Dean Richards.
"His calibre speaks for itself in terms of the trophies he has won and the impact he has had in the game, and we're really looking forward to welcoming him into our squad.
"He hits some super lines in midfield, gets over the gain line and his link-up play will really bring the best out of the players around him. We have some outstanding young talent within our squad, but Luther just brings that experienced head which will help those guys to develop."
Newcastle won all 15 games they played in the 2019-20 Championship season before it was ended by coronavirus and their promotion back to the top flight was confirmed by the Rugby Football Union in April.
They will replace Saracens, who were relegated because of persistent salary cup breaches.
Burrell scored four tries in 15 games for England between 2014 and 2016 and said he wanted to return to the 15-a-side game after Warrington terminated his contract with them.
"I met Dean Richards for a bite to eat, I could see straightaway he's just a totally straightforward bloke, and that's how you get the best out of me," he said.
"I just like the honesty around where they see me, and that's what I need. I don't want to be the guy on the sidelines, I want to be showing my worth to the group, and I feel like I can make a big contribution here.
"I was a lot heavier when I played union the first time round - somewhere around 112kg - and I dropped down to around 101-ish. I'm now up to 104kg, which I think is going to be my ideal size, and I'm just excited about bringing that aspect of my game into union.
"I've got no regrets about going over to league, because it was the fresh challenge that I needed at the time. I'll look back on it as a positive experience - I wanted to test myself, and I think I'll come back as a better player for it."