Hercules is known for his many adventures, which took him to the far reaches of the Greco-Roman world. One cycle of these adventures became canonical as the "Twelve Labours", but the list has variations. One traditional order of the labours is found in the Bibliotheca as follows:

Side adventures

Hercules had a greater number of "deeds on the side" (parerga) that have been popular subjects for art, including:

• Side adventures
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  Killing a fire-breathing Cacus (Sebald Beham, 1545)

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  Holding up the sky for Atlas (based on Heinrich Aldegrever, 1550)

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  Wrestling with Achelous (16th-century plaque)

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  Fighting the giant Antaeus (Auguste Couder, 1819)

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  Retrieving Alcestis from the underworld (Paul Cézanne, 1867)

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  Freeing Prometheus (Christian Griepenkerl, 1878)

The Latin name Hercules was borrowed through Etruscan, where it is represented variously as Heracle, Hercle, and other forms. Hercules was a favorite subject for Etruscan art, and appears often on bronze mirrors. The Etruscan form Herceler derives from the Greek Heracles via syncope. A mild oath invoking Hercules (Hercule! or Mehercle!) was a common interjection in Classical Latin.

Hercules had a number of myths that were distinctly Roman. One of these is Hercules' defeat of Cacus, who was terrorizing the countryside of Rome. The hero was associated with the Aventine Hill through his son Aventinus. Mark Antony considered him a personal patron god, as did the emperor Commodus. Hercules received various forms of religious veneration, including as a deity concerned with children and childbirth, in part because of myths about his precocious infancy, and in part because he fathered countless children. Roman brides wore a special belt tied with the "knot of Hercules", which was supposed to be hard to untie. The comic playwright Plautus presents the myth of Hercules' conception as a sex comedy in his play Amphitryon; Seneca wrote the tragedy Hercules Furens about his bout with madness. During the Roman Imperial era, Hercules was worshipped locally from Hispania through Gaul.

Germanic association

Tacitus records a special affinity of the Germanic peoples for Hercules. In chapter 3 of his Germania, Tacitus states:

... they say that Hercules, too, once visited them; and when going into battle, they sang of him first of all heroes. They have also those songs of theirs, by the recital of this barditus as they call it, they rouse their courage, while from the note they augur the result of the approaching conflict. For, as their line shouts, they inspire or feel alarm.

Some have taken this as Tacitus equating the Germanic Þunraz with Hercules by way of interpretatio romana.

In the Roman era Hercules' Club amulets appear from the 2nd to 3rd century, distributed over the empire (including Roman Britain, c.f. Cool 1986), mostly made of gold, shaped like wooden clubs. A specimen found in Köln-Nippes bears the inscription "DEO HER", confirming the association with Hercules.

In the 5th to 7th centuries, during the Migration Period, the amulet is theorized to have rapidly spread from the Elbe Germanic area across Europe. These Germanic "Donar's Clubs" were made from deer antler, bone or wood, more rarely also from bronze or precious metals.They are found exclusively in female graves, apparently worn either as a belt pendant, or as an ear pendant. The amulet type is replaced by the Viking Age Thor's hammer pendants in the course of the Christianization of Scandinavia from the 8th to 9th century.

After the Roman Empire became Christianized, mythological narratives were often reinterpreted as allegory, influenced by the philosophy of late antiquity. In the 4th century, Servius had described Hercules' return from the underworld as representing his ability to overcome earthly desires and vices, or the earth itself as a consumer of bodies.^[7] In medieval mythography, Hercules was one of the heroes seen as a strong role model who demonstrated both valor and wisdom, while the monsters he battles were regarded as moral obstacles.^[8] One glossator noted that when Hercules became a constellation, he showed that strength was necessary to gain entrance to Heaven.^[9]

Medieval mythography was written almost entirely in Latin, and original Greek texts were little used as sources for Hercules' myths.

In 1600, the citizens of Avignon bestowed on Henry of Navarre (the future King Henry IV of France) the title of the Hercule Gaulois ("Gallic Hercules"), justifying the extravagant flattery with a genealogy