El Djem
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.