Hecate: Mistress of Magic - Ronald Hutton

Hecate started as the ruling goddess of the Asian region of Caria, and got taken over by the Greeks as the only one able to operate in every realm of the cosmos. This then gave her special responsibility for travellers, doorways and restless ghosts. That slowly darkened her image, so that she became associated with the night, the moon, and magicians. By the Roman period, she was the goddess of sorcery par excellence, invoked for all sorts of enchantments, good or bad. In the late ancient worl...