Titan (Marvel Comics)

In the Marvel Universe, Saturn's moon Titan is the fictional home of the Titanian Eternals. It first appeared in Iron Man #55 (Feb 1973) and was created by Jim Starlin and Mike Friedrich. The Titanians, also known as Titans, were later retconned as being an offshoot of the Eternals, which had been created separately by Jack Kirby.

Fictional history
The colony of Titanian Eternals was founded about 750,000 years ago in the aftermath of a devastating civil war among the first generation of Earth's Eternals. The Eternals Uranos and Chronos led opposing factions, which clashed in a conflict of ideals over the Eternals' destiny as a people. Chronos' side prevailed, and Uranos and his surviving followers were exiled into space and landed on the planet Uranus. There, they discovered a supply depot guarded by a Kree Sentry. When the Eternals destroyed the Sentry and raided the outpost, the Kree armada came to investigate, thinking Earth’s solar system to be devoid of intelligent life. The armada destroyed the Eternals’ spacecraft, forcing them to crash on the moon Titan, where they hid from the Kree. There, the small group of survivors formed a colony beneath the surface of the moon, employing artificial life systems. These Eternals eventually fell prey to internal strife, and all of them but Sui-San were killed. A'lars, who had gone into voluntary exile, arrived on Titan, and the two Eternals began to repopulate the Titan colony.

These new Titanian Eternals achieved much scientifically and socially, not the least of which was ISAAC, an immense computer system that could monitor and maintain all of the life support functions of the inner world.

Under A'lars' leadership, Titan became a haven for peace. Then, A'lars (also known as Mentor) sired the last two of his numerous children: Eros and Thanos. Thanos was born a mutant, and grew up with dark visions of conquest and destruction. Thanos left Titan, recruited an army of mercenaries, and returned to attack. Only 100 of Titan's thousands of inhabitants survived, and Sui-San perished in the slaughter. Eventually, the Titanians rebuilt the colony and restored it to a place of meditation and the pursuit of knowledge.