Gabriel Magalhaes has had his shirt number confirmed by Arsenal after completing a move from Lille.
The defender marks the first arrival at the Emirates this summer but he does not look like the last.
Mikel Arteta had made strengthening his backline a priority after a leaky year at the back.
William Saliba is already set to make a difference this campaign after arriving from his loan at Saint-Etienne.
But the Gunners boss wants to partner him up with a left-footed centre-back and has got his wish in the form of Gabriel.
A bid of around £27m was accepted from Lille and the Brazilian rejected moves from Napoli and Everton.
Furthermore, his shirt number has been confirmed and he will wear the No. 6 jersey next season.
Others to wear the same shirt include former captains Tony Adams, Martin Keown and Laurent Koscielny, the Frenchman being the last man to do so.
Gabriel would be happy to emulate their careers at Arsenal, while other legends include David Rocastle, Charlie Nicholas and Steve Bould.
The signing was announced on social media, with Magalhaes joining fellow Brazilians Luiz and Willian on a video call.
Technical director Edu said: "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.
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"Gabriel is a player of high quality and Mikel and his coaches are looking forward to integrating him into the club."
Gabriel admitted messages on social media swayed his decision, telling the club's official website : "So many fans were sending me messages asking me to join Arsenal, and that played a big part in me signing for this club.
"I know the history and traditions of this club and it is a pleasure being here. I am very happy and hope I can contribute to many titles with the Arsenal shirt.
"It was a very surreal experience, there were offers coming from a few different clubs.
"I spoke a lot with my family and my agents, I also spoke with some of Lille’s directors, but as I said, this club’s history and traditions and the team project for the next few years were very motivational for my decision to come here.
"So here I am, wearing the Arsenal shirt, I will give my best for it and come on you Gunners!"