Achilles Heel-The Myth

 Achilles was the son of Thetis and Peleus, the bravest hero in the Trojan war, according to Greek mythology.

When Achilles was born, his mother, Thetis, tried to make him immortal by dipping him in the river Styx. As she immersed him, she held him by one heel and forgot to dip him a second time so the heel she held could get wet too. Therefore, the place where she held him remained untouched by the magic water of the Styx and that part stayed mortal or vulnerable.

Achilles fought heroically against the Trojans, but was killed by Paris,  who shot him with an arrow from behind.  Paris's hand was guided by Apollo who took revenge for the death of his son.

To this day, any weak point is called an "Achilles heel". We also refer to the strong tendon that connects the muscles of the calf of the leg with the heel bone as the "achilles tendon".

Excerpted from:  Achilles the Heel and Achilles