The name given to the type of pottery produced in the late 19th century by Robert Wallace Martin and his three brothers, Charles, Walter, and Edwin at their studio in Southall, Middlesex. Robert trained at the Lambeth School of Art and, as well as working for Doulton, he also undertook some stone carving for the Houses of Parliament, which gave him a taste for the grotesque. With his brothers he set up a studio in 1877; they worked as a team, designing, making, and decorating their own pieces, in the spirit of the Arts and Crafts Movement. Using salt-glazed stoneware they produced models and vessels of medieval inspiration, especially grotesque bird jars, with removable heads, and jugs decorated with faces. Their studio closed in 1914, but their techniques and methods of working show them to be precursors of 20th-century studio potters.
http://www.museumoflondon.org.uk/ceramics/pages/subcategory.asp?subcat_id=842&subcat_name=Martinware Description and illustrations on Museum of London website.