How they are related
This is Poseidon, the Greek god of the sea. His weapon is a trident that was made by the three Cyclopes. The connections he has with other gods and Titans are below. Enjoy!
This is Poseidon's father, Cronus. He is the Titan lord of time, and his weapon is a scythe. He swallowed his children because he had been told that they were going to overthrow him. When Poseidon's brother Zeus was born, his mother, Rhea, tricked Cronus into swallowing a stone and hid her new child in Crete. Eventually, Zeus grew up and forced Cronus to regurgitate his brothers and sisters. After that there was a war, and Cronus lost, so he became imprisoned in the lowest level of the underworld, Tartarus.
This is Poseidon's mother, Rhea. She is the sister and wife of Cronus, and she is considered the mother of the gods. Rhea is one of the Titans, and her parents are Uranus and Gaea. She is the mother of Poseidon and all five of his siblings.
This is Zeus, the Olympian god of the sky. His Roman name is Jupiter, and his weapon is a lightning bolt made by the three Cyclopes. He married one of his sisters, Hera.
This is Hades, Poseidon's oldest brother. His Roman name is Pluto, and he is the Greek god of the underworld. The three-headed dog shown in this picture is his sacred animal, Cerberus. He is married to Persephone, who he took to the underworld with him after he abducted her from his sister, Demeter.
This is Demeter, one of Poseidon's three sisters. She is the Greek goddess of harvest and agriculture. Her Roman name is Ceres. She has a daughter named Persephone, who is married to Hades.
This is Hestia, Poseidon's oldest sister. She is the Greek goddess of the hearth (a fire used to make offerings to the gods), and her Roman name is Vesta. She never married, even though she was proposed to by Apollo, the Greek god of music, and her own brother, Poseidon. She never left Mount Olympus or participated in any war, which is why she is respected by all of the Olympian gods.
This is Poseidon's sister, Hera. Her Roman name is Juno, and she is the Greek goddess of marriage. She is married to her brother, Zeus, and they had four children: Ares, the Olympian god of war, Hebe, the goddess of youth, Eilithyia, the goddess of childbirth, and Hephaestus, the Olympian god of fire and forges.