The 22-year-old has signed a long-term deal at the Emirates and will wear the number six shirt.

The Gunners fought off the likes of Napoli, Manchester United, PSG and Everton to secure Gabriel's signature following a lengthy pursuit this summer.

Gabriel impressed for Lille last season as he played 34 times in all competitions, helping them to a fourth-place finish in Ligue 1.

He becomes the second player to move between the clubs in the last 12 months after Arsenal signed Nicolas Pepe in a club-record £72 million deal last summer.

Head coach Mikel Arteta described the Brazilian as a player with 'outstanding attributes' and believes he will improve Arsenal defensively.

“We welcome Gabriel to Arsenal," said Arteta.

"He has many qualities which will make us stronger as a defensive unit and as a team.

"He has proved with Lille that he is a defender with many outstanding attributes and we are looking forward to watching him grow as an Arsenal player."

Technical director Edu added: "We are delighted to have signed Gabriel.

"He is a player we have been studying for a while and he was in demand from many clubs, so we are proud to have agreed and completed this transfer with Lille and the player.

"Gabriel is a player of high quality and Mikel and his coaches are looking forward to integrating him into the club."

Gabriel becomes the second Brazilian to join Arsenal this summer after Willian arrived on a free transfer from Chelsea.