Gilded bronze Roman "Hercules of the Theatre of Pompey", found near the Theatre of Pompey in 1864, (Vatican Museums, Rome)
Hercules is the Roman name for the Greek hero Herakles or Heracles; the Romans adopted the Greek stories about Heracles essentially unchanged, adding only a bit of anecdotal detail of their own.
Hercules is a god with a difference. He started out a mortal, and then joined the ranks of the gods in Olympus. What sets him apart would have to be his immense strength, courage, intelligence, and integrity. He is more hero than god and is even today one of the most popular and remembered of all mythical gods. He is in fact, the only god chosen by Disney to be immortalised as an animated feature, even though it was distorted beyond all recognition. That should count for something.
He was born Heracles to the mortal woman Alcmene and you guessed right, Zeus when on one of his dishonourable escapades. This time he took the form of her husband Amphitryon, who was away at war and fathered Hercules. Apparently Amphitryon returned later that day, and she had to go through the motions a second time, and this resulted in the birth of another son Iphicles a day later, known as the brother of Hercules. The Greek name Heracles gave way to the more popular Roman version which has endured to this day.
The news of the birth of yet another love child reached the tired ears of Hera, the wife of Zeus and she once again set off on one of her jealous wife trips. She sent two poisonous snakes to the crib of the babe which the aforementioned babe squeezed to death and played with till he grew weary and took a nap. Hera threatened, “I’ll be back,” and continued to torment Hercules right into his adulthood. The handsome young man soon met and married Megara, the daughter of King Creon, while on of his expeditions and they soon had a happy family saga going.
But Hera had neither forgotten nor forgiven Hercules the sins of his father, and send a frenzy to haunt him. This caused him to kill his family and rant like a madman. When he came out of his frenzy the poor chap went out of his mind with remorse. On the verge of suicide he appealed to Apollo for guidance and was told to do penance by performing twelve tasks for Eurystheus who was a distant relative. Hercules completed every one of them exhibiting great strength, presence of mind, and patience.
He was absolved of his crime and went on to marry Deianira in a bid to start a new life. But a robe she presented him doused in what she believed was a love potion, eventually poisoned him and he was in a great deal of pain. It proved intolerable for him and he stepped into a burning pyre to end his misery. But Zeus intervened and decided enough was enough. He brought him up to Olympus, implored Hera to leave him alone, and proceeded to crown him immortal.