Hercules encountered many people in his travels and labors. For convenience, I've listed the following as friend, family, or enemy of Hercules. As usual, such labels are simplistic.
Also see the Apollodorus Concordance for names and places in Apollodorus' account of the Labors of Hercules. This is based on the Loeb edition of the Library of Apollodorus, a 2nd Century B.C. Greek scholar, who wrote a Chronicles and On the Gods. It is thought that the Library (Bibliotheca) was written by someone a few centuries later, but it is still referred to as the Library of Apollodorus or Pseudo-Apollodorus.
Eurystheus is Hercules' cousin an king of Mycenae and Tiryns. After Hera had tricked an oath out of Zeus that the boy born that day who was his descendant would become king, she caused Eurystheus to be born early and Hercules, who was due, was held back until Eurystheus was born. It was for Eurystheus that Hercules performed the 12 labors.
Hesione was a sister of King Priam of Troy. When their father, Ling Laomedon, ruled Troy, Hesione was exposed to a sea monster. Hercules rescued her and gave her as a concubine to his follower Telamon. Hesione was mother of Telamon's son Teucer, but not Ajax.
Hylas - Friend of Hercules
Public Domain. Courtesy of WikipediaHylas was a beautiful young man whom Hercules loved. They joined the Argonauts together, but then Hylas was taken by nymphs.
Iolaus - Friend and Family of Hercules
Public Domain. Courtesy of WikipediaIolaus, son of Iphicles, was a charioteer, companion, and favorite of Hercules. He may have married Hercules' wife Megara after Hercules killed their children in one of his fits of madness. Iolaus helped Hercules in the labor to destroy the Lernaean Hydra by cauterizing the neck after Hercules severed the head.
Iphicles - Family of Hercules
Iphicles was the twin brother of Hercules. He was born of Alcmene and his father was Amphitryon. Iphicles was the father of Hercules' favorite, Iolaus.Hercules offered to save King Laomedon's daughter from the sea monster if Laomedon would give him his special horses as reward. Laomedon agreed, Hercules rescued Hesione, but Laomedon reneged on the deal, so Hercules took revenge.
Lapiths - Usually Friends of Hercules
Hercules came to the aid of a grandson of Hellen, King Aegimius of the Dorians, in his boundary conflict with King Coronus of the Lapiths. King Aegimus promised Hercules a third of the land, so Hercules killed the Lapith king and won the conflict for the Dorian king. Keeping his part of the bargain, King Aegimius adopted Hercules son Hyllus as heir.Linus - Enemy of Hercules
Linus was the brother of Orpheus and taught Hercules writing and music, but when he struck Hercules, Hercules retaliated and killed him. Hercules was excused, by Rhadamanthys, for the murder because he was retaliating against an act of aggression. Nonetheless Amphitryon sent him away to a cattle farm. [Apollodorus 2.4.9]Megara - Family of Hercules
For saving the Thebans from the tribute to the Minyans, Hercules was awarded Megara, daughter of King Creon for wife. They had three children. [Apollodorus 2.4.11] In Apollodorus 2.4.12 Hercules was driven mad after defeating the Minyans. He threw his children and two of Iphicles' children into a fire. Other stories put the madness after Hercules' return from Hades. Hercules may have married his wife to a surviving nephew, Iolaus.Minyans - Enemy of Hercules
The Minyans were collecting a tribute from the Thebans under King Creon for 20 years. One year when they sent out their tribute collectors, Hercules apprehended them and cut off their ears and noses and sent them back to their king, Erginus. The Minyans retaliated, and attacked Thebes, but Hercules defeated them. His step-father Amphitryon may have been killed in this battle.
