Short answers, pulled from the story.
The story of Heracles began in the Neolithic hunter culture where traditions of shamanistic crossings into the netherworld shaped his mythological development. Walter Burkert identified this core origin in ancient texts from 1985.
The earliest evidence of popular cult worship appeared in the 6th century BCE through an inscription found at Phaleron. By the 4th century BCE, Heracles had become identified with the Phoenician God Melqart showing how myths evolved over time.
Eurystheus decided to give Heracles ten labours but added two more after completion resulting in the Twelve Labors of Heracles. If he succeeded he would be purified of his sin and granted immortality.
The ancient Greeks celebrated the festival of the Heracleia on the second day of the month Metageitnion falling in late July or early August. This event commemorated the death of Heracles and honored him as both hero and god simultaneously.
Commodus and Maximian particularly adopted this figure during their reigns to strengthen imperial identity through cultural syncretism with Melqart. The royal house of Macedonia claimed lineal descent from the hero primarily for purposes of divine protection and legitimation of actions.