The Chapel of St John the Baptist is a unique masterpiece of European art, with enormous historical, cultural and artistic importance. It was constructed in its entirety in Rome in the 1740s for a commission by the Portuguese monarch King John V, partially shown at the pontifical city (in 1747 and 1749) and then reassembled in the Church of Sao Roque in Lisbon. This is a complete and comprehensive study of the chapel, encompassing its design and construction, as well as the extraordinary collections within. Magnificently illustrated with a stunning selection of photographs, this beautiful volume brings together the studies of a number of experts on the chapel's architecture, sculpture, mosaics, metalwork and outstanding collections of silver, textiles, furniture and books. Specialist and non-specialist alike will not fail to be captivated by the extraordinary beauty of this unparalleled architectural and artistic creation.