The Hecatic Strophalus, or Hecate's Wheel, is the symbol of the pre-Grecian goddess Hecate, who was absorbed in to Greco-Roman culture as a goddess of crossroads, witches, and the undead. Though often thought of as a crone type figure in new age religions like Wicca, Hecate was always pictured with a youthful appearance in early Greek and Roman artifacts, leading many to speculate that perhaps she was originally a early Carian goddess, of spring or nature.
Whatever her origins she was considered a prominent goddess to the Hellenic peoples. She was associated with midwifery and healing, and was supposed to guard doors, gates and other portals against evil spirits. It is this act that earned her the title "Queen of Ghosts".
It is unknown exactly who created the symbol known as Hecate's Wheel, or when. It thought to have been inspired by a verse in Isaac Cory's version of the Chaldean Oracles, written in 1836. The Chaldean Oracles are collection of bits and pieces of earlier works describing and commenting on a single unknown prophecy, mystery poem, or ritualistic work. Needless to say the collection of work is not considered one of much scholastic value today, as the poem itself is nonexistent and many of the remnants cannot be authenticated. To date I am completely unable to verify the verse itself, or even which of Isaac Cory's books the translation was supposed to have appeared in.