Hercules (or Heracles as he was known to the Greeks) was regarded as the mightiest of the Greek heroes. He became famous for the twelve labors that he performed for King Eurystheus. One of the stipulations placed upon Hercules while performing his labors was that he carry them out without any assistance.
Although Hercules was something of a "lone ranger" during his famous labors, these labors helped provide salvation for a number of larger groups. This is brought out especially in Euripides' Heracles, in which the tragedian calls attention to a variety of groups for whom Hercules can be regarded as a savior. On one level, Hercules became regarded as the saviour of the people of Thebes by defeating Erginus and the Minyans. His capturing or killing of various dangerous creatures led to him being considered the savior of Greece. According to Euripides, Hercules even managed to save the gods themselves by helping restore the honor that human beings owed them. Thus, in his play, Euripides has even the goddess Madness show respect for Hercules:
This man, against whose house you are sending me, has made himself a name alike in heaven and earth; for, after taming pathless wilds and raging sea, he by his single might raised up again the honors of the gods when sinking before man's impiety" (E.P. Coleridge translation).
Thus, Heracles, as an individual, is able to save his city, his country, and even the gods themselves.