Adrian Mariappa has returned to Watford after four years away from the club.
The 29-year-old defender has signed a three-year deal with the Hornets after ending a three-year spell with Crystal Palace earlier in the summer.
Jamaica international Mariappa started his senior career with Watford in 2005 after coming through the Hertfordshire club's academy and went on to play more than 200 times for the Hornets.
Mariappa, who had a season with Reading in 2012/13, is one of 12 new additions made by Watford boss Walter Mazzarri this transfer window.