Portsmouth have completed the signing of Bournemouth captain Jason Pearce for an undisclosed fee.
The 23-year-old defender has re-joined Pompey on a three-year deal after four years with the Cherries.
Portsmouth boss Steve Cotterill told the club website: "He's not just for now - he's also for the future.
"He's tough, can pass it out of the back and has a good strike with his left foot. We hope to develop him into a better player than he already is."
Peterborough wanted to sign the defender but he had a sell-on clause in his contract which entitled Pompey to 50% of any transfer fee.
Posh chairman Darragh MacAnthony said on social network site Twitter: "Gutted to lose out on Pearce, we matched Pompey's transfer offer but he chose them such is life. Wish lad and his new club well. We move on."
Pearce played 187 games for the Cherries after leaving Fratton Park in 2007.
Meanwhile, Bournemouth have failed in a bid for 24-year-old AFC Wimbledon midfielder Steven Gregory.
The Dons have described the bid as "a long way below the club's valuation" and say the Cherries have said they will not increase their offer.