Pepe had many options to leave Lille, with top European clubs after his signature.
But he remained patient and eventually chose Arsenal. Now he has spoken about why he made the move.
"I chose to come here because it's a club with a lot of ambition," Pepe said to the club's website.
"They have the dream of coming back to the Champions League and I am also an ambitious person, so the choice was very logical.
"I am attracted to the Premier League because it is an extremely intense championship and the best league in the world.
"The idea is to win the Europa League and that is a goal of ours. It's a European event and our goal is to do better than last season. I believe we will."