Olympians was the original name for the New Olympians, before they withdrew to New Olympus. Some were believed by the humans of ancient Greece and Rome to be gods, while others were feared and persecuted as monsters, prompting their decision to isolate themselves on New Olympus.
Real World Background
The Olympians, in Greek mythology, were the twelve gods of Mount Olympus, over whom Zeus ruled. The other eleven were Hera, Poseidon, Athena, Ares, Hephaestus, Aphrodite, Apollo, Artemis, Demeter, Hermes, and Dionysus. Hestia, Zeus's sister and the goddess of the hearth, was originally one of the Olympians, but gladly abdicated from their number when Dionysus was admitted to Olympus.
The exact relation between the New Olympians and the Greek gods is uncertain, since the bulk of the New Olympians encountered in Gargoyles resemble more the "monsters" of Greek mythology than to the gods (with the exception of Boreas, Helios, and in the unmade The New Olympians (spin-off)The New Olympians spin-off, Jove). Greg Weisman has commented that some of the younger Greek gods may have been Olympians, such as Apollo and Artemis, while the older ones, such as the Titans, may have been members of the Third Race who begat the Olympians - he has, incidentally, called these beings "Children of Mab", suggesting that the early events of Greek mythology may have taken place before Oberon overthrew Queen Mab.