Iapetus (Japetus, the Piercer)
Iapetus was the Titan god of mortal life span or god of death. He presided over the time line of all the mortals. His nickname, "the piercer", actually meant that he came for the life of the mortals in the terms of violence. In the other words, when Iapetus decided that one's time had passed, he brought violent death upon him. He was also known as the Pillar of the west. Together with his other three brothers Coeus, Hyperion and Crius they presided as the Pillars of holding Heaven and Earth apart. He was one of six sons of Uranus and Gaea and is mentioned by Apollodorus as one of the five brothers, all but Oceanus, who participated in rebellion against Uranus and later attacked him. When they overcame him, the four brothers probably held him down, while Cronus castrated him.
Titanomachy
After decapitating and dethroning their father Uranus, Iapetus stood by his brother Cronus who became the new ruler of the Cosmos. During the golden age of the Titans, he married his niece Clymene, daughter of Oceanus and Tethys. Together they had four sons who overshadowed their father in the time of war and in later times of Olympians. There are, however, few statements by different authors which indicate that the role of Iapetus was very important and equate him with the role of Cronus. Homer himself states that Cronus and Iapetus were equal in power, while Nonnus and Valerius Flaccus state that in the Titanomachy, at some point Zeus fought with Iapetus and according to Valerius, who goes even further, it is said that Zeus became the ruler of Cosmos after winning the fierce battle with Iapetus.
When the war between Titans and Olympian gods had started, his sons were also mentioned to had played their part. Atlas and Menoetius sided with the Titans, while Prometheus and Epimetheus chose Olympians. Atlas became the leader of the Titans in the war and caused Olympians more than few setbacks. Menoetius was said to be very vicious during the war, brutally slaying allies of the Olympians until Zeus himself struck him down with his thunderbolt and sent him to Tartarus, because of his mad presumption and exceeding pride. Prometheus and Epimetheus, although they had also played important part in the war, are also like their father , very rarely or almost never mentioned in sources that are preserved. Instead they played important role after the war, with creation of men and animals.
When the war was over, Iapetus was sent to Tartarus, where he was re-united with brothers and many relatives. He was described by Homer as one of the more destructive titans who was seated beside Cronus in the depths of Tartarus. However, according to Aeschylus' lost play , he was later released by Zeus from Tartarus with the rest of the titans.