Gosport-born Ritchie, 34, started his career with Pompey, progressing from the academy to the first team at Fratton Park, and has now returned to his boyhood club.

He made 215 appearances for Newcastle after joining the club in the summer of 2016, and scored 25 goals - the last of which was an injury-time equaliser against his former club Bournemouth in February 2024.

Ritchie played a huge role as United lifted the Championship title in his first season, then became a cult hero as the club re-established themselves as a top flight club over the course of the following years before securing Champions League football for the 2023-24 campaign.

He wrote a heartfelt message to the Newcastle supporters when it was announced that his contract would not be renewed in May, and upon rejoining Portsmouth Ritchie said: "I've always had in my mind that I had unfinished business at the football club.

"I love the club, as we all do. I'm really excited for the challenge we've got, but also excited for the personal challenge and I'm delighted that I'm back."

Portsmouth boss Blues boss John Mousinho told the official Pompey website: "Everyone will know what Matt is all about because he's had a fantastic Premier League career.

"I'm sure all the fans have tracked his incredible progress since he was last at the club and been pleased by what he's achieved.

"It's a transfer that's been talked about for a long time and it's amazing that we've been able to get it done.

"As well as playing in the top-flight for a number of seasons, Matt also has plenty of experience at this level, having been promoted from the Championship a couple of times.

"It's one of those signings that will provide a real boost around the place because he's a fantastic player and in very good physical condition. We're very excited to have him here."