Jayawardene, the 38-year-old former Test captain, scored 1,493 runs in 55 Twenty20 internationals and will feature in 12 of 14 group games for the county. After announcing the move he said: 

“

The club has a tradition of successful overseas players and I will be doing my best to join that illustrious list.

”

Matthew Maynard, Somerset’s director of cricket, said: “To have the top two run-scorers in the history of the World T20 walking out into the middle at Taunton is something that I hope the members and supporters will be looking forward to.”

Gayle announced in January that he would appear for six matches for Somerset after scoring 328 runs in his three appearances for them last season. However the county failed to make the knockout stages of last year’s competition, which was won by Lancashire.