The Titans were all offspring of Gaea and Ouranos. There were 12 titans. The brothers: Okeanos, Koios, Krios, Hyperion, Iapetos and Kronos. The sisters: Theia, Rhea, Themis, Mnemosyne, Phoebe and Tethys. Kronos was not only the youngest but he was also the bravest.
Okeanos is the eldest of his eleven other siblings. He rules all if the odd bodies of water (not the Mediterranean Sea, that’s Poseidon’s domain. We’ll get to that later). At some point, Okeanos married his sister Tethys. They had many children called the Oceanids. Tethys and Okeanos had so many children that it began to flood so the two siblings had to divorce to prevent it from happening again.
Koios was not extremely important in Greek Mythology like his brother Kronos was, however his descendants were the gods Apollo (god of poetry, music and many other things.. see page Apollo for more) and Artemis (goddess of the hunt and the moon). He married his sister Phoebe. His daughter Asteria wasn’t well known in Greek Mythology. However, his other daughter Leto was the mother of the god Apollo and the goddess Artemis (As mentioned earlier). Koios was one of the four titans who held down his side of the cosmos (his father). Koios was a titan pillar. He was titan of the North.
Krios wasn’t known for much. He fathered Perses, Astraios and Pallas, after spending time with Eurybia. She was a daughter Gaia and Pontos. Later on, when Astraios and Eos, the Dawn, created Eosphoros and the stars and winds. The second titan pillar was Krois. Krois held down the South end.
Hyperion was one of the eight titans who married their sibling. He ended up marrying Theia. His children played a massive role (Not as big as the children of Cronos and Rhea though). He had a daughter named Selene (Original goddess of the moon), Helios (Original god of the sun) and Eos (Dawn). Hyperion was one of the four titans who held down his side of the cosmos while Kronos was dealing with his father. Hyperion was most likely the pillar of the east since his daughter was Dawn.
Similar to to his brother Koios, Iapetos wasn’t as important as his offspring and descendants. He fathered Atlas, Prometheus, Epimetheus and Menoitios. He got together with one of the Okeanides to create his children. Iapetus was one of the four titans who held down one of the four corners of the cosmos. Iapetos was most likely pillar of the west. This was while Kronos castrated his father Ouranos with his scythe. He was nicknamed the Piercer and was god of mortal life span.
Kronos has a long story unlike most of his siblings. He was probably the most know titan of all. He was the one who volunteered to murder his father by castrating him with a scythe. He married the most beautiful sister. Mother Rhea. Rhea was mother of the very first immortal gods and goddesses. The eldest was Hestia. Then came out Hera, Demeter, Poseidon, Hades and Zeus. (Find out more about Kronos and his story in Chapter: The Destruction of Ouranos).