This book examines the development of the mosque from the hijra (A.H.1/A.D.622) to the fall of the Umayyad dynasty (A.H.133/A.D.750). The aims of the book are two-fold. Firstly, to consider how those mosques for which we only have literary evidence may be approached for study; and secondly, to trace the development of the mosque in the archaeological record. The archaeological evidence for the mosques at W asi t, Isk af Ban3 Junayd, K ufa and the Aq a mosque at Jerusalem are examined in detail; there follows an examination of the form and layout of the various types of mosque encountered in the physical record, and a discussion of some architectural influences which may have affected the development of form. The book also considers thosemosques for which no secure archaeological evidence may be cited and attempts to pick apart previous attempted reconstructions of these buildings which were often based on an uncritical approach to the literary sources.