After Benfica confirmed Dias' departure, City formalised the arrival of the Portugal defender on Tuesday, with Nicolas Otamendi going the other way.

City will hope Dias can help to solve the defensive issues that undermined their title defence last season, as they finished 18 points behind champion Liverpool.

And Dias feels the marriage of his and City's styles will allow him to succeed and live up to the billing at the Etihad Stadium.

"To have the opportunity to join a club like Manchester City is a fantastic opportunity for me and one I couldn't turn down," Dias said.

"Their success speaks for itself. They have been the dominant team in England over the last few years, playing an attacking brand of football which I feel suits my own game.

"It is really exciting to be part of such a talented squad and to play for a world-class manager like Pep Guardiola, who has a proven track record of developing young players like myself.

"I believe I can improve here, at a club whose ambitions match my own and I will give everything to be successful and win titles."

City's director of football Txiki Begiristain said: "Ruben is a player we have admired for some time and we have been impressed with how he has progressed at Benfica.

"He has developed into a real leader and as a defender, he has all the attributes we are looking for. He is strong in the air, good in one-v-one situations and technically, he is very good, so we are confident he can thrive in our system.

"He is young but has experience playing for a top European club in Benfica and we're really pleased we've been able to sign him.

"He is another talented addition to the squad and someone who is only going to get better working under Pep."