There is a subject for tragedy there; and it was brilliantly treated in Euripides' Iphigenia in Aulis, which was probably left unfinished at his death. But our play chooses a later moment of the story. In reality Artemis at the last moment saved Iphigenia, rapt her away from mortal eyes and set her down in the land of the Tauri to be her priestess. (In Tauris is only the Latin for "among the Tauri.") These Tauri possessed an image of Artemis which had fallen from heaven, and kept up a savage rite of sacrificing to it all strangers who were cast on their shores. Iphigenia, obedient to her goddess, and held by "the spell of the altar," had to consecrate the victims as they went in to be slain. So far only barbarian strangers had come: she waited half in horror, half in a rage of revenge, for the day when she should have to sacrifice a Greek. The first Greek that came was her own brother, Orestes, who had been sent by Apollo to take the image of Artemis and bear it to Attica, where it should no more be stained with human sacrifice. If we try to turn from these myths to the historical facts that underlay them, we may conjecture that there were three goddesses of the common Aegean type, worshipped in different places. At Brauron and elsewhere there was Iphigenia ('Birth-mighty'); at Halae there was the Tauropolos ('the Bull-rider,' like Europa, who rode on the horned Moon); among the savage and scarcely known Tauri there was some goddess to whom shipwrecked strangers were sacrificed. Lastly there came in the Olympian Artemis. Now all these goddesses (except possibly the Taurian, of whom we know little) were associated with the Moon and with child-birth, and with rites for sacrificing or redeeming the first-born. Naturally enough, therefore, they were all gradually absorbed by the prevailing worship of Artemis. Tauropolis became an epithet of Artemis, Iphigenia became her priestess and 'Keybearer.' And the word 'Tauropolis,' which had become obscure, was explained as a reference to the Tauri. The old rude image of Tauropolis had come from the Tauri, and the strange ritual was descended from their bloody rites. So the Taurian goddess must be Artemis too. The tendency of ancient polytheism, when it met with some alien religion, was not to treat the alien gods as entirely new persons, but assuming the real and obvious existence of their own gods, to inquire by what names and with what ritual the strangers worshipped them.