Steve Kirby has signed a three-year contract with Somerset after being granted his release from neighbours Gloucestershire.
The seam bowler had the final two years of his agreement with Gloucestershire cancelled at his own request to allow him to pursue his ambition of playing in the top-flight of the LV County Championship.
Kirby, who has taken 434 first-class wickets at an average of 28.03, is keen to press his claims for an England chance, having represented the second-string Lions.
Somerset will be the 32-year-old's fourth county in a much-travelled career that has included stints with Leicestershire and Yorkshire.
"Somerset are putting together the nucleus of a side who can be contenders in all forms of cricket and I am looking forward to competing for a place because competition is what sport is all about for me," he told Somerset's official website.
"The club has a great infrastructure as well as a very good team. I can assure their supporters I have plenty of fire left in my belly and I'm looking forward to the challenge of bowling at Taunton."
Director of cricket Brian Rose also revealed Somerset have put in 28 days notice of approach for another Gloucestershire paceman, Gemaal Hussain, and Nottinghamshire seamer Charlie Shreck.