Watford have signed Scunthorpe defender David Mirfin on a two-year deal after his contract expired at Glanford Park.
The 26-year-old played 25 times last season as the Iron finished bottom of the Championship.
"He's someone who we think has challenged hard at a club who've had tough tests every season," Hornets boss Sean Dyche told the club website.
Meanwhile Watford academy product Bernard Mensah has agreed a three-year professional deal.
The 16-year-old striker, who is a first-year scholar, will turn professional when he becomes 17 in December, but will continue to train with the youth team.
Mirfin arrives after three years at Scunthorpe, where he made 111 appearances, scoring five goals.
The centre-half, who started his career in the Huddersfield youth set-up, went on to feature 181 times for the Terriers.
He becomes Watford's second signing of the summer, following midfielder Craig Forsyth's switch from Dundee, and Dyche has insisted that there will be more arrivals.
"There's others in the pipeline, that's for sure," he said. "Sometimes they take a bit of time to materialise."