Achilles Achilles: Mythical Hero and Real Tendon According to ancient Greek mythology, Achilles was the Greek hero and greatest warrior of the Trojan War. His exploits were chronicled by Homer in the Iliad, one of Western civilization’s first great epic poems; Alexander the Great used the title Descendent of Achilles; and Achilles was a lead character in three movies: Helen of Troy (1956), Helen of Troy (TV 2003), and Troy (2004). Achilles' mother Thetis was one of the fifty Nereids. Nereids were friendly women who: lived in the Mediterranean Sea, associated with Poseidon (God of the Sea), helped sailors during storms, rode dolphins and sea turtles, and could predict the future. Achilles’ father Peleus was King of the Myrmidons and one of the Argonauts who accompanied Jason on the quest for the Golden Fleece. All the gods and goddesses except Eris (goddess of conflicts) were invited to Thetis's and Peleus's wedding.  Eris did not like being excluded, so she threw a golden apple into the wedding banquet.  The apple was inscribed “to the most beautiful”; which led to an argument between the beautiful goddesses Hera, Athena and Aphrodite; which later contributed to the beginning of the Trojan war.

There are two versions of how Thetis tried to immortalize Achilles. In the earlier version she anointed him with ambrosia (a drink of the gods that reinforced their immortality) and then put him in a fire so that all his mortal parts would burn away, leaving only his anointed (and therefore immortal) parts. However, Peleus interrupted her and pulled Achilles out of the fire before his heel was burned. In the later version she dipped Achilles in the sacred river Styx, making every part of him that touched the water invulnerable. However, Thetis held Achilles by his heel while dipping him, so his heel was not touched by the water. In both versions, Achilles’ heel remained mortal, while the rest of his body became immortal. Achilles’ heel was Achilles' only vulnerability.   During the Trojan War Achilles was a seemingly invincible warrior. He captured over 20 Trojan towns, and killed many Trojan warriors and their allies. These included: Hector, Prince of Troy and the 2nd greatest warrior in the Trojan War; Memnon, King of Ethiopia and Greek historian; Cycnus, son of Poseidon and King of Colonae; and Penthesilia, Queen of the Amazon warriors.  Later, Paris (who started the Trojan war by kidnapping Helen from Greece), aided by Apollo (God of Music and Archery), shot an arrow into Achilles’ heel and Achilles died of the wound.   As a result of the Achilles legend, the expression Achilles heel came to mean a small but fatal vulnerability, and the tendon connecting the heel to the calf became known as the Achilles tendon.