In 1770 the Derby porcelain factory acquired the Chelsea porcelain factory, and from that period, until the closure of the Chelsea factory in 1784, the products of both factories bear the same mark - an anchor and the letter 'D', and are often called 'Chelsea-Derby'. The Derby factory then began to produce new models of figures and groups, and was the first factory in England to use biscuit porcelain, following the lead of the Sèvres factory in France. The biscuit models were also made in glazed and painted porcelain, being cheaper than biscuit, which needed special attention in firing to avoid any defects that could not be covered up. This example makes use of both techniques, and the pale biscuit is set off well by the deep blue and rich gilding, further combined in the lapis lazuli effect.King George III (reigned 1760-1811) and the royal family were represented in three biscuit groups after an engraving after a painting by Johann Zoffany (1735-1810) of 1770. The models are listed among the new productions of the factory in 1773. The King is shown leaning against a plinth decorated with trophies of art, music and learning, on top of which are placed the royal insignia.