obverse of his gold coins. The effect on iconoclast opinion is unknown, but the change certainly caused Caliph Abd al-Malik to break permanently with his previous adoption of Byzantine coin types to start a purely Islamic coinage with lettering only. This appears more like two opposed camps asserting their positions (pro and anti images) than one empire seeking to imitate the other. More striking is the fact that Islamic iconoclasm rejected any depictions of living people or animals, not only religious images. By contrast, Byzantine iconomachy concerned itself only with the question of the holy presence (or lack thereof) of images. Thus, although the rise of Islam may have created an environment in which images were at the forefront of intellectual question and debate, Islamic iconoclasm does not seem to have had a direct causal role in the development of the Byzantine image debate; in fact Muslim territories became havens for iconophile refugees. However, it has been argued that Leo III, because of his Syrian background, could have been influenced by Islamic beliefs and practises, which could have inspired his first removal of images. The goal of the iconoclasts was to restore the church to the strict opposition to images in worship that they believed characterized at the least some parts of the early church. Theologically, one aspect of the debate, as with most in Christian theology at the time, revolved around the two natures of Jesus. Iconoclasts believed that icons could not represent both the divine and the human natures of the Messiah at the same time, but only separately. Because an icon which depicted Jesus as purely physical would be Nestorianism, and one which showed Him as both human and divine would not be able to do so without confusing the two natures into one mixed nature, which was Monophysitism, all icons were thus heretical. Leo III did preach a series of sermons in which he drew attention to the excessive behaviour of the iconodules, which Leo III stated was in direct opposition to Mosaic Law as shown in the Second Commandment. However, no detailed writings setting out iconoclast arguments have survived; we have only brief quotations and references in the writings of the iconodules and the nature of Biblical law in Christianity has always been in dispute. Sources A thorough understanding of the Iconoclast period in Byzantium is complicated by the fact that most of the surviving