National Gallery, London
The Wilton Diptych is one of the most precious paintings in the National Gallery, because most small art works from Middle Ages in England were destroyed. This painting shows King Richard II of England being presented to the Virgin Mary by his three patron saints. It is painted in tempera; the colours are mixed with egg. The word "diptych" means it is in two parts and can be closed like a book. The background is covered with thinly beaten gold leaf. The blue is made from ground-up semi-precious stone, lapis lazuli. It may have been painted as a wedding present for the King while he was in France .