How soon is too soon? Private collectors are selling off works as little as a few weeks after lending them to high-profile shows

We talk to Martin Gayford about his book Modernists and Mavericks and sitting for portraits by Freud and Hockney. And we explore a show celebrating the Signals gallery, where Latin American and European avant-gardes converged.

Rapper P. Diddy identified as buyer of the Chicago-based painter's Past Times

Acquisition heralds triptych of London shows dedicated to Dean

More than 150 works will be on display, from those executed early in his career to some whose paint is still wet