It seems to be an odd but undeniable fact that Zeus had two sons named Herakles ... one was born to Alkmene in Thebes circa 1300 BCE ... the other was born to an unnamed mother when modern humanoids first appeared on Earth ... that would be at least 40,000 years ago!
Most people seem to lump the two together and don’t even try to sort out the obvious differences between the two different Herakles’ ... the whole thing came as quite a shock to me but now that I know the truth, the life and deeds of Herakles seem to make a whole lot more sense ... let’s refer to them as ancient-Herakles and Herakles.
When ancient-Herakles encountered Prometheus, we humans were a pitiable lot ... we had only had the benefit and comfort of fire for thirteen generations ... Prometheus defied Zeus to give us fire and was chained to the Caucasus Mountains for his defiance ... Herakles killed the eagle Zeus had sent to torment Prometheus and then broke the chains which held Prometheus.
The ancient-Herakles was presumably fully divine and thus immortal ... as to what became of the ancient-Herakles we simply don’t know.
And then came a second Herakles ... he was born to a mortal woman and therefore only semi-divine.
The second Herakles completed the Twelve Labors assigned to him by his cousin Eurystheus ... he accompanied Jason and the Argonauts but had to leave them before they got to Kolchis to retrieve the Golden Fleece ... Herakles was mortally wounded by his wife Deianeira and tried to take his own life in order to end his suffering ... he was taken from his funeral pyre by either the goddess Nike or the goddess Athene ... he became immortal and, although he did not become one of the twelve Olympians, he was worshiped as a hero and a god throughout the ancient world.
I personally have no doubt that the second Herakles was a real man because his descendants ruled in various parts of Greece for over five hundred years after his death/ascension.