in Persian miniatures and Moghul and Ottoman art influenced by them. Flaming halos derived from Buddhist art surround angels, and similar ones are often seen around Muhammad and other sacred human figures. From the early 17th century, plainer round haloes appear in portraits of Mughal Emperors and subsequently Rajput and Sikh rulers; despite the more local precedents art historians believe the Mughals took the motif from European religious art, though it expresses a Persian idea of the God-given charisma of kingship that is far older. The Ottomans avoided using halos for the sultans, despite their title as Caliph, and they are only seen on Chinese emperors if they are posing as Buddhist religious figures, as some felt entitled to do. Egypt and Asia Roman art The halo represents an aura or the glow of sanctity which was conventionally drawn encircling the head. It first appeared in the culture of Hellenistic Greece and Rome, possibly related to the Zoroastrian hvarena – "glory" or "divine lustre" – which marked the Persian kings, and may have been imported with Mithraism. Though Roman paintings have largely disappeared, save some fresco decorations, the haloed figure remains fresh in Roman mosaics. In a 2nd-century AD Roman floor mosaic preserved at Bardo, Tunisia, a haloed Poseidon appears in his chariot drawn by hippocamps. Significantly, the triton and nereid who accompany the sea-god are not haloed. In a late 2nd century AD floor mosaic from Thysdrus, El Djem, (illustration) Apollo Helios is identified by his effulgent halo. Another haloed Apollo in mosaic, from Hadrumentum, is in the museum at Sousse. The conventions of this representation, head tilted, lips slightly parted, large-eyed, curling hair cut in locks grazing the neck, were developed in the 3rd century BC to depict Alexander the Great (Bieber 1964; Yalouris 1980). Sometime after this mosaic was executed, the Emperor began to be depicted with a halo, which was not abandoned when they became Christian; initially Christ only had one when shown on a throne as Christ in Majesty. Christian art The halo was incorporated into Early Christian art sometime in the 4th century with the earliest iconic images of Christ, initially the only figure shown with one (together with his symbol, the Lamb of God). Initially the halo was regarded by many as a representation of the Logos of Christ, his divine nature, and therefore in very early (before 500) depictions of Christ before