German billionaire's vast art collection on show in Berlin

He made his fortune with industrial hardware and used it to collect priceless art, from medieval treasures to modern masterpieces by Pablo Picasso, Henry Moore and Andy Warhol.

German billionaire Reinhold Wuerth, 80, known as the "screws king" for his global business empire, has since the 1960s built up one of Europe's largest and most glittering private art collections.

From Friday, 400 of his works go on show in Berlin's Martin Gropius Bau gallery under the title From Hockney to Holbein - a crowning achievement for Wuerth, who built up the family business from his humble beginnings in the postwar years.