As a child, Hephaestus was literally kicked out of Olympus by his mother, Hera. He was an immortal god, so he survived, but was maimed for life, unable to walk without assistance. He crawled back up to Olympus, where he was given the status of the god of fire and the forge by his compassionate father, Zeus.
He took Aphrodite, the goddess of love and beauty, for his wife.
Do you, Aphrodite, take Hephaestus to be your husband?
Being a child of Zeus, Hephaestus had many siblings, including, but not limited to, Athena, Artemis, Apollo, and Ares-and those are only some of the godly siblings!
Later, in his forge, Hephaestus made such magical items as Hades' cap of invisibility, Achilles' shield, Apollo's sun chariot, a throne to trap and humiliate his mother, Hera, as revenge, and his own two robotic helpers, who supported him when he walked.
Hephaestus made up for his lameness by using his huge arm strength to make such items for (and, in some cases, against) his fellow Olympians. Some such creations of note are Hades's helm of invisibility, Apollo's sun chariot, and a throne to trap and humiliate his mother as revenge for throwing him from Olympus so long ago.
Aphrodite was not happy with having one so ugly as Hephaestus as her husband. She cheated on him with Ares, the god of war. Neither of them suspected that Hephaestus knew, however, and so he set a trap. He set up the bed to entrap the adulterers in an inescapable mesh net. When the trap worked, the two were hung from a pole in the middle of the gods' city for all to see.