In ancient Roman religion and Hellenic neopaganism, Vulcan is the god of beneficial and hindering fire, including the fire of volcanoes. He is also called Mulciber ("smelter") in Roman mythology and Sethlans in Etruscan mythology. He was worshipped at an annual festival on August 23 known as the Volcanalia.
Vulcan was identified with the Greek god of fire and smithery, Hephaestus.
The Romans identified Vulcan with the Greek smith-god Hephaestus, and he became associated like his Greek counterpart with the constructive use of fire in metalworking. A fragment of a Greek pot showing Hephaestus found at the Volcanal has been dated to the 6th century BC, suggesting that the two gods were already associated at this date. However, Vulcan had a stronger association than Hephaestus with fire's destructive capacity, and a major concern of his worshippers was to encourage the god to avert harmful fires. His festival, the Vulcanalia, was celebrated on August 23 each year, when the summer heat placed crops and granaries most at risk of burning. During the festival bonfires were created in honour of the god, into which live fish or small animals were thrown as a sacrifice, to be consumed in the place of humans. Vulcan was among the gods placated after the Great Fire of Rome in AD 64. In response to the same fire, Domitian (emperor 81–96) established a new altar to Vulcan on the Quirinal Hill. At the same time a red bull-calf and red boar were added to the sacrifices made on the Vulcanalia, at least in that region of the city.
Through his identification with the Hephaestus of Greek mythology, he came to be considered as the manufacturer of art, arms, iron, jewellery and armor for various gods and heroes, including the thunderbolts of Jupiter. He was the son of Jupiter and Juno, and husband of Maia and Venus. His smithy was believed to be situated underneath Mount Etna in Sicily.
As the son of Jupiter, the king of the gods, and Juno, the queen of the gods, Vulcan should have been quite handsome, but, baby Vulcan was small and ugly with a red, bawling face. Juno was so horrified that she hurled the tiny baby off the top of Mount Olympus.
Vulcan fell down for a day and a night, landing in the sea. Unfortunately, one of his legs broke as he hit the water, and never developed properly. From the surface, Vulcan sunk like a pebble to the cool blue depths where the sea-nymph, Thetis, found him and took him to her underwater grotto, and raised him as her own son.
Vulcan had a happy childhood with dolphins as his playmates and pearls as his toys. Late in his childhood, he found the remains of a fisherman's fire on the beach and became fascinated with an unextinguished coal, still red-hot and glowing.
Vulcan carefully shut this precious coal in a clamshell and took it back to his underwater grotto and made a fire with it. On the first day after, Vulcan stared at this fire for hours on end. On the second day, he discovered that when he made the fire hotter with bellows, certain stones sweated iron, silver or gold. On the third day he beat the cooled metal into shapes: bracelets, chains, swords and shields. Vulcan made pearl-handled knives and spoons for his foster mother, he made a silver chariot for himself, and bridles so that seahorses could transport him quickly. He even made slave-girls of gold to wait on him and do his bidding.
Later, Thetis left her underwater grotto to attend a dinner party on Mount Olympus wearing a beautiful necklace of silver and sapphires, which Vulcan had made for her. Juno admired the necklace and asked as to where she could get one. Thetis became flustered causing Juno to become suspicious and, at last, the queen god discovered the truth: the baby she had once rejected had grown into a talented blacksmith.
Juno was furious and demanded that Vulcan return home, a demand that he refused. However he did send Juno a beautifully constructed chair made of silver and gold, inlaid with mother-of-pearl. Juno was delighted with this gift but, as soon as she sat in it her weight triggered hidden springs and metal bands sprung forth to hold her fast. The more she shrieked and struggled the more firmly the mechanical throne gripped her; the chair was a cleverly designed trap.
For three days Juno sat fuming, still trapped in Vulcan's chair, she couldn't sleep, she couldn't stretch, she couldn't eat. It was Jupiter who finally saved the day, he promised that if Vulcan released Juno he would give him a wife, Venus the goddess of love and beauty. Vulcan agreed and married Venus. He later built a smithy under Mount Etna on the island of Sicily. It was said that whenever Venus is unfaithful, Vulcan grows angry and beats the red-hot metal with such a force that sparks and smoke rise up from the top of the mountain, to create a volcanic eruption.
To punish mankind for stealing the secrets of fire, Jupiter ordered the other gods to make a poisoned gift for man. Vulcan's contribution to the beautiful and foolish Pandora was to mould her from clay and to give her form. He also made the thrones for the other gods on Mount Olympus.