A bronze statue of the cat goddess Bastet (Louvre Museum).
The earliest evidence of felines (specifically, lions) as deities comes from a c. 3100 BC crystal cup decorated with an image of the lion-headed goddess Mafdet. The goddess Bastet was originally depicted as a fiercely protective and warlike lioness, like Sekhmet, but as Bastet’s image “softened” over time, she became more strongly associated with domestic cats.
As cats were sacred to Bast, the practice of mummification was extended to them, and the respect that cats received after death mirrored the respect with which they were treated in everyday life. The Greek historian Herodotus wrote that in the event of a fire, men would guard the fire to make certain that no cats ran into the flame. Herodotus also wrote that when a cat died, the household would go into mourning as if for a human relative, and would often shave their eyebrows to signify their loss.
Such was the strength of feeling towards cats that killing one, even accidentally, incurred the death penalty. Another Greek historian, Diodorus Siculus, describes an interesting example of swift justice imposed upon the killer of a cat: about 60 BC, he witnessed a Roman accidentally kill an Egyptian cat. An outraged mob gathered and, despite pleas from pharaoh Ptolemy XII, killed the Roman.