Jan van Eyck was the greatest artist of the early Netherlands school. He held high positions throughout his career, including court painter and diplomat in Bruges. So outstanding was his skill as an oil painter that the invention of the medium was at one time attributed to him, with his brother Hubert, also a painter. Van Eyck exploited the qualities of oil as never before, building up layers of transparent glazes, thus giving him a surface on which to capture objects in the minutest detail and allowing for the preservation of his colours. Nowhere is this better displayed than in this portrait of Giovanni di Arrigo Arnolfini, a merchant from Lucca and a frequent visitor to Bruges, and his wife Giovanna Cenami. The signature on the back wall - 'Jan Van Eyck was here, 1434' - and his reflection in the mirror has led many to believe that he was a witness to their marriage.