Sol Campbell made his decision to join Portsmouth after several options to move abroad fell through.
Campbell was introduced to the crowd before Pompey's friendly with Porto
The 31-year-old signed a two-year deal with the Fratton Park club on Tuesday.
"There was interest abroad and those things didn't work out," said Campbell. "I stated that if it didn't work out I would look at home.
"I've joined because it is a professional club going places with great potential. It was a decision which was very easy to make."
Campbell added that he had been impressed by the enthusiasm shown by Pompey.
"There were other situations which were up in the air but Portsmouth were the first ones to express an interest two or three months ago," said the former Tottenham and Arsenal defender.
If we get the right players and right attitude then Europe is within our reach
And after making his final appearance for Arsenal in last season's Champions League final, Campbell said that he wanted to help his new club qualify for European competition.
"If we get the right players and right attitude then Europe is within our reach," said the England defender.
"Once you've enough players who have done it before it makes it a lot easier to win games, hold on to games and nick results.
"Those points here and there add up at the end of the season.
"Europe is where I want to play again and I'm sure this club wants to be there as well. Everyone is ambitious here so why not?"
Pompey boss Harry Redknapp said that securing a player of Campbell's stature is a sign of the club's ambition.
"It's a great signing, Sol is an absolutely top-class player and a great centre-half," said Redknapp.
"In my opinion it's a statement of where we want to go. This is going to be a great club to be associated with."
Campbell was introduced to his new club's supporters before Pompey's pre-season friendly against Porto.
The Portuguese team took the lead though Lisandro before Svetoslav Todorov equalised with a diving header.
Marek Cech scored the winner for Porto with a free-kick that took a deflection off Linvoy Primus.