The underlining theme of my research during the past 20 years has been the study of the technology involved in the production of early vitreous materials; that is, glazed stones, faience, coloured frits, glass and glazed pottery. One major topic has been the study of early glazed stones and faience from Egypt and the Near East, and their inter-relationship with subsequent beginnings of glass and glazed pottery production. A second major topic has been the study of the introduction of lead glazes in the Roman period and tin-opacified glazes in the Islamic world. Related to this, has been the study of the inter-relationship of Islamic ceramics to contemporary Chinese porcelain and the subsequent influence of Islamic ceramics on the development of glazed ceramics and porcelain in Europe.