Midfielder Adlene Guedioura has joined Watford for an undisclosed fee just before the closure of the summer transfer window.
The 29-year-old Algerian international joins the Premier League new boys having made 19 appearances for Palace since signing from Nottingham Forest two years ago.
Last season Guedioura enjoyed two loan spells at the Hornets where he made 17 appearances, helping them win promotion to the top-flight.
The club would like to wish good luck to Adlene at Vicarage Road.