Overview
An atef is the White Crown of Upper Egypt fitted with a pair of tall ostrich plumes at the sides and often a sun disc and ram’s horns at the base. Purely ceremonial, its towering shape belonged to gods and to the king acting in their sphere.
How it is worn
It is set on the head over the brow, sometimes above a wig or the nemes, its plumes rising high and its horns curling at the base, worn for funerary and cultic occasions rather than daily rule. Osiris is almost always shown crowned with it.
History
The atef appears from the Old Kingdom in religious contexts and grew ever more elaborate through the New Kingdom and later periods, gathering horns, discs, and extra plumes. It is above all the crown of Osiris and of the king in his role among the gods.