"Valencia have reached an agreement with Arsenal Football Club on Thursday for the transfer of Francis Coquelin, who becomes a new black and white player until June 30, 2022", the club said in a statement.
The Frenchman, who signed a new deal with the Premier League club just past year, has now inked a contract with the Spanish side that runs through 2022.
"It wasn't to be and now this opportunity has come up".
"It was incredible. My loan at Charlton gave me a lot of confidence to come back with a lot of energy and I think you saw that in the first game I came back and played in. It's a big challenge, and a new start in my life for me, which I'm very excited about".
Coquelin, 26, arrived at Arsenal from French side Laval in 2008 and went on to make 160 first-team appearances.
Coquelin has revealed that Arsenal star Santi Cazorla played a big part to his move.
"He added: "[Cazorla] told me it's an excellent club which I will not regret joining.
The strong tackler told L'Equipe that "I am at an important stage in my career".
And he insists he's ready to play in Valencia's league trip to Deportivo this weekend. I trust what he tells me'.
"My first year was awesome, winning the FA Youth Cup in 2009, then coming back from my loan at Charlton I thought I wasn't going to play for Arsenal, but I am happy I had the chance to show what I can do".
"I have chosen a club with a great past, and with a family atmosphere".