Blackwell leaves Somerset after spending eight years at the club
Former Somerset captain Ian Blackwell has said his decision to leave the club was an extremely difficult one.
The 30-year-old all-rounder, who made one Test appearance for England, has agreed to join Durham despite having two years left on his Somerset deal.
Blackwell said: "I achieved many great career goals - winning three trophies with the team and making my debut for England being amongst the highlights.
"Making this decision has been the hardest thing I've ever had to do."
He added: "I hope I am able to utilise my move to Durham County Cricket Club so I am able to progress in all formats of the game and push for future England recognition."
Somerset director of cricket Brian Rose said: "Ian has been a wonderful player for Somerset County Cricket Club.
"He has been hugely popular with the supporters and has been a great entertainer.
"He has gone on to win England recognition, with 34 one day international appearances and one Test cap."
Blackwell, a big-hitting batsman and a left-arm spinner, provides new captain Will Smith with plenty of experience having played 147 first-class matches.