José Berardo, known as ‘Joe’, is your average diamond miner – just a chap who dabbles in hotels, tobacco, telecommunications, likes the odd drop of wine from his vineyard and has a £220 million art collection (its value per Christie’s last year). And just like any other regular Joe – or Tom, Dick or François – Berardo opened his own museum last year, in a tourist area in the west of Lisbon. Housed within the site of the Belém Cultural Centre, which had given the space of its Exhibition Centre over to the collection, Berardo’s holdings will be on permanent view until 2016. It was a deal that took ten years to negotiate – the thorny issues raised when private collections go on view in, and in this case replace the programme of, publicly funded spaces – but it means the Portuguese public now have a world-class museum of impressively historical range: from Mondrian to Modigliani; Andy Warhol to David Hockney; de Kooning to Francis Bacon; as well as Portuguese stars such as Pedro Cabrita Reis. In return, the state will have the option to buy the collection at the end of its ten-year tenure. Museum visitors – 23,000 of whom traipsed through in the first 24 hours – seemed happy; the Belém centre director António Mega Ferreira, who resigned as president of the board the day after the opening, did not.