- Altars feature frequently in Greek legend, for heroes were always making sacrifices to the gods, so it is not surprising to find an altar among the stars. But this altar is a special one, for it was used by the gods themselves to swear a vow of allegiance before their fight against the Titans, according to Eratosthenes and Manilius. That clash, known as the Titanomachy, was one of the most significant events in Greek myth.