England's Simon Kerrigan has signed a new two-year contract with Lancashire.
The spinner, 24, took 58 first-class wickets last season as Lancashire won Division Two, making his England debut in this summer's final Ashes Test.
He is among 15 to sign new deals along with captain Glen Chapple, Tom Smith, Karl Brown, Paul Horton and Kyle Hogg.
Andrea Agathangelou, Stephen Parry, Liam Livingstone, Oliver Newby, Jordan Clark, Alex Davies, Arron Lilley, Luke Procter, and Luis Reece all signed too.
Lancashire cricket director Mike Watkinson said in September that the club were committed to keeping a "Lancashire core" to their team next season.
"It's great that all 15 players, except Andrea, are products of our system," said Watkinson.
"That is a great endorsement of the strength and effectiveness of the cricket played across the county."
Brown, Hogg, Parry, Horton, Reece and Smith have all committed for a further two seasons, while Chapple, who will be 40 at the start of next season, has signed a one-year deal.
Second XI players Clark, Davies, Lilley and Procter have all agreed two-year contracts and youth scholar Liam Livingstone has been handed a one-year professional deal.
The deals follow the signing of England one-day wicketkeeper Jos Buttler from Somerset.