But, not all the Titans were imprisoned there. Certainly Oceanus, the great world encircling river, seems to have remained free, and in fact, seems not to have fought on the Titan's side at all.  In Hesiod, Oceanus sends his daughter Styx, with her children Zelus (Envy), Nike (Victory), Cratos (Power), and Bia (Force), to fight on Zeus' side against the Titans, while in the Iliad, Hera says that, during the Titanomachy, she was cared for by Oceanus and his wife the Titaness Tethys. Aeschylus' Prometheus Bound, has Oceanus free to visit his nephew Prometheus sometime after the war.  Like Oceanus, Helios, the Titan son of Hyperion, certainly remained free to drive his sun-chariot daily across the sky, taking an active part in events subsequent to the Titanomachy.  The freedom of Oceanus, along with Helios (Sun), and perhaps Hyperion (to the extent that he also represented the sun), would seem to be the result of cosmological necessity, for how could a world encircling river, or the sun, be confined in Tartarus?