This ancient rock picture near Egypt's Nile River was first spotted by an explorer more than a century ago—and then almost completely forgotten.

Scientists who rediscovered it now think it's the earliest known depiction of a pharaoh.

The royal figure at the center of the panel wears the "White Crown," the bowling pin-shaped headpiece that symbolized kingship of southern Egypt, and carries a long scepter. Two attendants bearing standards march ahead of him; behind him, an attendant waves a large fan to cool the royal head. A hound-like dog with pointed ears walks at the ruler's feet. Surrounding the king are large ships, symbols of dominance, towed by bearded men pulling on ropes.

The picture, which was engraved on a sheer cliff face in the desert northwest of the city of Aswan, was probably created between roughly 3200 and 3100 B.C., according to researchers who published their discovery in December's issue of the journal Antiquity.

At around the same time that the picture was crafted, northern and southern Egypt were united under the reign of a supreme monarch, or pharaoh. The pharaoh in the picture may be Narmer, the king who overcame the last vestiges of northern resistance to southern rule and is considered by many to be Egypt's founding pharaoh...

...Recognition of the uniqueness of these artworks has been a long time coming. The site was discovered in the 1890s by a British scholar who published a sketch of some of the pictures, but didn't recognize their significance. Another scholar photographed the Nag el-Hamdulab tableaux in the 1960s, but never published his findings. Finally a Norwegian scientist and his team reported in 2009 that they'd rediscovered two of the artworks.