In Greek mythology, Iphicles (also called Iphiclus) was the mortal half-twin brother of Heracles and one of the hunters of the Calydonian boar. Born of Alcmene by her human husband Amphitryon — while Heracles was fathered by Zeus — he was the younger of the twins by one night. Though he grew into a strong man, he could never match his famous brother; he was the father of Heracles' charioteer Iolaus and fought and died beside Heracles in his wars.
Adapted from Wikipedia, "Iphicles" · CC BY-SA 4.0
I.Family
Iphicles was the son of Alcmene and her human husband Amphitryon, whereas Heracles was Alcmene's son by Zeus. He also had a sister, Laonome, who married either Euphemus or Polyphemus.
By his first wife Automedusa, daughter of Alcathous, Iphicles fathered Iolaus, who became Heracles' charioteer. Afterwards he fathered two further children by Pyrrha, the younger daughter of Creon.
II.Mythology
Iphicles was one night younger than his half-brother Heracles. When Heracles, still an infant, strangled the snakes that had been sent to their cradle — by Hera, or in another account placed there by Amphitryon — Iphicles was frightened by them. He grew into a strong man, but could never match his famous brother.
When Heracles was driven mad through Hera's influence, he threw into the fire the two children Iphicles had fathered by Pyrrha, and they perished as a result.
Iphicles accompanied Heracles on his expedition against King Laomedon of Troy. On arriving, Iphicles and Telamon were sent ahead by Heracles to claim the mares promised to him, but Laomedon threw them into prison. The prince Priam supplied them with swords to escape and revealed his father's plans against them.
III.Death
After Heracles completed his Labours, King Eurystheus drove him, together with Alcmene and Iphicles, out of Tiryns. In the war that followed against Hippocoon of Sparta, Iphicles was killed in battle, and Heracles was left inconsolable over the death of his half-brother.
An alternative tradition places his death during Heracles' campaign against the Eleans and Augeas, in which Iphicles was wounded by the Molionides of Elis. He was carried to Pheneus to recover, but died of his wound there; the people of Pheneus buried him, and he was honoured with a hero-shrine (heroum).