Stone panel from the North-West Palace of Ashurnasirpal II (Room I)

The use of magic to protect buildings and their owners was an old tradition in Mesopotamia. Images of supernatural creatures would be buried under doorways or set up at the entrances of palaces and temples. Their supposed magical strength would frighten away evil-wishing demons. These figures with wings may possibly be supernatural creatures known as apkallu. They wear horned headdresses to show their divinity and carry buckets and what appear to be fir cones used to sprinkle, presumably, water from the bucket for purification. The stylized tree between the spirits is usually called a Sacred Tree or even, misleadingly, a Tree of Life. It bears some distant relationship to the palm-tree, having a palmette on top of the trunk and a trellis of smaller palmettes around it. The palmette is a distinctly Assyrian version of a symbol which had long been known in Mesopotamia and the Levant. Its exact meaning is not clear, but the flowing streams and vegetation could be taken as representing the fertility of the earth, or more specifically, Assyria itself. Though no two Sacred Trees were exactly alike, the arrangement of the branches on the two sides of each tree was always identical.