Saints have confirmed the signing of Dusan Tadic for a fee believed to be around £11m.
The 25-year-old Serbian has signed a four deal to seal his switch from FC Twente and become Ronald Koeman’s first St Mary’s signing.
Tadic is seen as the ideal replacement for Adam Lallana and comes with an outstanding reputation.
He enjoyed an outstanding season with Twente last term, scoring 16 goals from midfield and helping the team to a third-place finish.
He also provided 14 assists and created an eye-catching total of 133 chances – in both categories, he led the way by some considerable distance in the Eredivise.
Tadic, who made his international debut at 19, has been capped 25 times by his country.
He has also attracted interest from both Schalke and Sevilla this summer, but Saints have won the race for his signature.
Tadic said: "It is a really nice feeling, this is a really nice club of which I have heard a lot of good things about. I have already seen the beautiful training centre and there are lots of nice people that work here including the coaches so I am really happy to be here.
"I watched a lot of the games last season and saw that the Club plays really nice football which will suit me because I like to play in the same way. The manager obviously knows me from the Dutch league so when he called me and told me his plan it was an easy decision to make.
"I know the manager well because he is one of the biggest Dutch legends in football, everyone knows him. He is a really good coach and you can always expect his teams to play well because he is leading them and because he is so good tactically. I am really excited to start playing for the club."
Koeman added: “It was very important to get this signing done – not only for me, but for the rest of the squad and for our fans. It’s fantastic news.
“We’ve lost some good players but we want to continue the ambition and philosophy of the club, so it’s a great signal to have brought in our first player.
“He’s a great player. I know him very well from Holland, where he had a great season last year.
“We now look forward to bringing in more players because we want to continue and maybe even better what Southampton did last season.”