Former Barcelona coach Tito Vilanova has died of throat cancer at the age of 45.
Vilanova led the Catalan club for a season after taking over from Pep Guardiola, but was forced to resign last summer because of ill health.
Barça said in a statement: "The club expresses their deepest condolences over the passing of Tito Vilanova , who died today in Barcelona at the age of 45."
Vilanova, a former midfielder who spent his playing career largely in the Spanish second division, was Guardiola's assistant for four years at the Nou Camp, the pair having previously worked together with the B team.
He was first diagnosed with parotid gland cancer in November 2011 and the disease returned in December 2012.
He was away from the team between December and late March as he underwent surgery and treatment, but still won the La Liga title before resigning in July last year.
Barça sent their "deepest condolences" to Vilanova's family and said they would be opening a space in the main grandstand at the Nou Camp for people to express their condolences.
The club's president said on Twitter: "Tito Vilanova was a wonderful person, and will never be forgotten at FC Barcelona. Thank you for everything you taught us. Rest in peace."
Vilanova led Barça to their highest ever points total for a La Liga season during his single season in charge, their 100 points a joint record for the division with Real Madrid.
Barca midfielder Cesc Fabregas paid an emotional tribute on his Facebook page.
He wrote: "Tito, thank you for all you have given to football and Barça .
"Personally, I met you 14 years ago and I can say that there are very few people like you. Thank you for always trusting me to help me improve and overcome personal and professional obstacles.
"We will always keep a place for you in our hearts. Rest in peace Tito."