the Virgin or a saint, were also widely utilized in Christian practices at this time. Relics, a firmly embedded part of veneration by this period, provided physical presence of the divine but were not infinitely reproducible (an original relic was required), and still usually required believers to undertake pilgrimage or have contact with somebody who had. The use of images had greatly increased during this period, and had generated a growing opposition among many in the church, although the progress and extent of these views is now unclear. Images in the form of mosaics and paintings were widely used in churches, homes and other places such as over city gates, and had since the reign of Justinian I been increasingly taking on a spiritual significance of their own, and regarded at least in the popular mind as capable of possessing capacities in their own right, so that "the image acts or behaves as the subject itself is expected to act or behave. It makes known its wishes ... It enacts evangelical teachings, ... When attacked it bleeds, ... [and] In some cases it defends itself against infidels with physical force ...". Key artefacts to blur this boundary emerged in c. 570 in the form of miraculously created acheiropoieta or "images not made by human hands". These sacred images were a form of contact relic, which additionally were taken to prove divine approval of the use of icons. The two most famous were the Mandylion of Edessa (where it still remained) and the Image of Camuliana from Cappadocia, by then in Constantinople. The latter was already regarded as a palladium that had won battles and saved Constantinople from the Persian-Avar siege of 626, when the Patriarch paraded it around the walls of the city. Both were images of Christ, and at least in some versions of their stories supposedly made when Christ pressed a cloth to his face (compare with the later, western Veil of Veronica and Turin shroud). In other versions of the Mandylion's story it joined a number of other images that were believed to have been painted from the life in the New Testament period by Saint Luke or other human painters, again demonstrating the support of Christ and the Virgin for icons, and the continuity of their use in Christianity since its start. G. E. von Grunebaum has said "The iconoclasm of the eighth and ninth centuries