Poseidon was the son of Cronus and Rhea, the god of the sea and one of the twelve Olympian gods. Together with his brothers, Zeus and Hades, Poseidon ruled over the world. After defeating Cronus and the Titans, the three brothers divided the world among themselves: Poseidon was given the sea, Zeus the heaven and Hades the underworld, while the Earth was shared among them. Poseidon is sometimes considered older and sometimes younger than his brother Zeus. According to Hesiod, he is older Zeus' brother whom Cronus, like the rest of his children, swallowed at birth. Later, Zeus freed his brothers and sisters, and together with them started a war against the Titans (see Zeus, Titans). After the victory of Olympians, by Gaea's advice, Zeus was chosen for the supreme ruler of the world, and he nominated duties to his brothers and sisters. Later, after the development of birthright, because of his function, Zeus was considered as the oldest, and Poseidon became his younger brother. According to one tradition, Rhea hid Poseidon from Cronus on the island Rhodes, where he was brought up by Telchines.
Although reluctantly, Poseidon had to obey his brother Zeus' will, and that's why the relationship between the two brothers wasn't always friendly. Together with Hera and Athena, Poseidon took part in the plot against Zeus, but they withdrew because of the threats of the giant Briareus. Therefore, the father of the gods did not favour Poseidon. He sent him with Apollo to serve the Trojan king Laomedon for a year and build the walls of Troy. However, Laomedon refused to give Poseidon the agreed salary, so Poseidon in revenge summoned a sea-monster which caused havoc among the Trojans. That was the beginning of Poseidon's aversion against the Trojans, and explains why Poseidon was on the Greek side in the Trojan war. But, at the beginning of the war, Poseidon could not accept the decision of the Greeks to fortify their camp by surrounding the ships with a wall, because he believed that was likely to diminish the glory he had earned in building the walls of Troy. Therefore, Zeus gave him a permission to destroy and cover with sand all walls built by mortals.
Poseidon often confronted other gods for the domination over some cities and regions. He disputed with Athena for the possession of Athenian Acropolis and Troezen region. He disputed with Hera over Argos, with Helios over Corinthian Acropolis, with Zeus over Aegina, and with Dionysus over Naxos. He was no lucky in these disputes, as judges almost always favoured his opponents. However, nobody ever disputed Poseidon's rule over the sea. With his trident, he could command the waves, cause storms, shake the earth, sink boats on the high sea, or cause springs to flow. When he walked on the Earth, the mountains and forests trembled. His battle cry was loud as if ten thousand men had made it. Poseidon was not only the master of the sea, but also of the lakes and rivers. With his wife Amphitrite, he lived in the magnificent golden palace in the depths of the Aegean sea. His chariot was pulled by the giant, golden maned horses, with such a speed that waves could hardly wet the bronze axle.
In the myth and cult, Poseidon was related to the horse. There is a legend saying that he created the first horse by hitting the rock with his trident. In another legend, the Earth created the horse when Poseidon's seed had fallen onto it. Poseidon was also a horse tamer and a protector of horse competitions. He gave a divine horses to many heroes, like Pelops (1), Peleus and Adrastus. As the sea god, Poseidon was often related to a bull, which symbolized the roar of the waves.
In the tradition in which Poseidon was brought up by Telchines, his first love was Halia, the sister of the Telchines, by whom he had six mighty sons and one daughter, Rhodus.
Poseidon's lawful wife was Amphitrite, the Nereus' daughter. He first saw her on the island Naxos, dancing with her sisters, and fell in love with her immediately. When he asked her to marry him, she refused and hid herself deep into the ocean. Then Poseidon sent a dolphin to look for her. The dolphin found her and convinced her to marry his master. As a reward, Poseidon placed the dolphin in the constellation. From then on Amphitrite shared Poseidon's kingdom. They had one son, Triton, and one daughter, Rhode.
Like his brother Zeus, Poseidon wasn't a faithful husband. He loved many goddesses and mortal women, to whom he approached in various forms, as stallion, bird, bull or dolphin. To win the love of the goddess Demeter, Poseidon transformed himself into a stallion and in that form he fertilized her. She bore him the wild horse Arion (1), and a daughter who was known only as the Mistress (Despoina).
From Poseidon's numerous love affairs, the most famous were those with Aethra, Amymone, Medusa, Celaeno (1), Chione (1), Alope and Tyro (see these names), with whom he had Theseus, Nauplius (1), Pegasus, Chrysaor, Lycus (2), Eurypylus (5), Pelias, Neleus (1), Eumolpus and Hippothoon.
Poseidon also fathered a certain number of monstrous and malignant beings, among which the most famous were the twin brothers Ephialtes (1) and Otus, Cercyon (1), Busiris and the Cyclops Polyphemus (2).
Poseidon is a very old deity that was worshipped in Greece since very early days, especially on the Peloponnese (Sparta, Mantinea, Taenoron). The tablets with the linear inscription found in Pylos, the capital city of the Poseidon's son Neleus (1), show that Poseidon was worshipped back in Mycenaean period as a principal god and that he was given lavish sacrifices. Later, his cult was spread throughout Greece, mostly in maritime towns.
Firstly, Poseidon was the god of the land waters, the creator of numerous springs (see Amymone), and he was responsible for the humidity and fertility of the soil. He was the tamer and master of horses, the creator of earthquakes and the powerful master of the sea. Poseidon was the protector of fishing and sailing, the founder of cities, tribes and nations. The horse and the bull were the animals sacrificed to him, usually by being thrown into the waves. The eight day in a month was dedicated to him and in his honour the chariot races were organized.
In the art, Poseidon is represented as an elegant, mature man, with thick curly hair and beard. His representations from the archaic period are very similar to those of Zeus; he is shown naked, still or in motion, wearing a long mantle. On the ceramic tablets from his sanctuary in Corinth (sixth century BC), Poseidon is shown riding a horse or driving a chariot with his wife Amphitrite. From fourth century BC, Poseidon is shown in his characteristic pose, leaned on his right leg on a rock, ship or dolphin, and holding a trident or fish in his hands.