A well-known figurative expression to denote a point of weakness or vulnerability but not necessarily fatal as in the classical myth of Achilles. As told in Homer’s Iliad during the siege of Troy, Achilles killed Hector in a famous duel outside the walls of the city. Although not mentioned in the Iliad, Paris avenged his brother Hector by shooting an arrow, possibly poisoned, into the heel of Achilles. When Achilles was a baby, his mother Thetis dipped him in the river Styx to make him invincible in battle. Unfortunately, the only part of Achilles’ body that did not benefit from the magical powers of the river was the heel by which his mother held him. In Greek mythology, the gods themselves were divided between the Greek and Trojan causes. As the story goes, Apollo guided the arrow to the one spot where Achilles was vulnerable. Although the story of Achilles heel is ancient, the figurative meaning of a point of weakness or vulnerability dates only from the 429/early 19th century. In anatomy, the tendon above the heel is known as the Achilles tendon and this was coined in 1693 by the Dutch anatomist Philip Verheyden about 100 years before the figurative use of the expression was adopted.