A detailed study of incised effigal slabs and brasses from London workshops from AD 1250 to 1400 and their relationship with the production of monumental brasses. It focuses on the Cumoys, Septvans, Seymour, Basyng, and Ashford styles from before the Black Death. 170 slabs from England and Wales are studied in terms of their style, inscriptions, date and distribution recreating a picture of the operations of the London marblers and their workshops. The authors conclude that it is possible that the incised slabs and brasses were made in the same workshops, and possible even by the same people. Fresh light is thrown upon the dating of early brasses. Illustrated throughout with photos and rubbings.