Knowledge of the Bible in the eastern church among the laity was predominantly gained through art rather than text, though the readings in the liturgy were of course an oral source of its contents. Despite some enthusiastic scholarly claims that literacy was higher in the East than in the West, there is no good reason to imagine that more that 10 per cent of the population could read the Bible text for themselves. Even for the literate and the priesthood, the most desirable manuscripts with the sacred text were those enhanced by illuminations. Such illustrated books rarely contained the complete Bible; one of the very few known illustrated examples is the tenth-century Bible of Leo Sakellarios, which contains one frontispiece picture for each chapter (surrounded by verses written by the lay commissioner). This book, now in the Vatican Library (BAV, Reg. gr. 1), consists today of only the first volume (Genesis–Psalms) out of two, and is the largest known Byzantine manuscript (410 × 270 mm). Normally illustrated manuscripts consisted of individual books or collected books (such as Octateuchs, psalters, Job, gospelbooks or lectionaries).

By the year 600 Byzantium had emerged as the leading Christian society in the Mediterranean, with Constantinople predominant as the capital city, New Rome, of the eastern Roman empire. With the rise of Islam in the seventh century, Byzantine territories in the eastern Mediterranean were suddenly much reduced, and confrontation with the Umayyad rulers based in Damascus and in control of the Holy Land was as much a cultural as a political challenge. Both faiths developed their own distinctive forms of art, and the identifying feature of the eastern church came to be seen as the icon, whereas Islam cultivated the display of the holy word of the Qurʾān. The aim of this chapter is to trace the emergence of the icon, and to track its development. This will involve a brief flashback to the origins of Christian art in the East as a way of contextualising Byzantine Iconoclasm, which controlled the character of artistic production from around 730 up to 843. Thereafter the Triumph of Orthodoxy, which was declared in 843 and commemorated annually on the first Sunday in Lent, meant the acceleration of the use of art in the church, and the creation in due course of a sacred environment which was in great part constructed by the charismatic role of the icon in church decoration.