Modern understanding of Greek mythology mythology to the still poorly understood pre-Hellenic societies of Greece, such as the Minoans and so-called Pelasgians. This is especially true in the case of chthonic deities and mother goddesses. Historians of religion were fascinated by a number of apparently ancient configurations of myth connencted with Crete: the god as bull — Zeus and Europa; Pasiphaë who yields to the bull and gives birth to the Minotaur; agrarian mysteries with a sacred marriage (Demeter's union with Iasion) etc. Crete, Mycenae, Pylos, Thebes and Orchomenus figure so large in later Greek mythology. For some, the three main generations of gods in
Greek mythology Nereids (who inhabited the sea), river gods, Satyrs, and others. In addition, there were the dark powers of the underworld, such as the Erinyes (or Furies), said to pursue those guilty of crimes against blood-relatives. In order to honor the Ancient Greek pantheon, poets composed the Homeric Hymns (a group of thirty-three songs). Gregory Nagy regards "the larger Homeric Hymns as simple preludes (compared with "Theogony"), each of which invokes one god". The gods of Greek mythology are described as having essentially corporeal but ideal bodies. According to Walter Burkert, the defining characteristic of Greek anthropomorphism is that "the Greek