520s BC births

Aeschylus (, ; ; /524 – /455 BC) was an ancient Greek tragedian often described as the father of tragedy. Academic knowledge of the genre begins with his work, and understanding of earlier Greek tragedy is largely based on inferences made from reading his surviving plays. According to Aristotle, he expanded the number of characters in the theatre and allowed conflict among them. Formerly, characters interacted only with the chorus.

Themistocles (; , Themistoklēs; ) was an Athenian politician and general. He was one of a new breed of non-aristocratic politicians who rose to prominence in the early years of the Athenian democracy. As a politician, Themistocles was a populist, having the support of lower-class Athenians, and generally being at odds with the Athenian nobility. Elected archon in 493 BC, he convinced the polis to increase the naval power of Athens, a recurring theme in his political career. During the first Persian invasion of Greece, he fought at the Battle of Marathon (490 BC), and may have been on

Athenian politician and father of Pericles (c.525–475 BC)

Chinese philosopher (c. 521–481 BC)

Cleostratus (; b. c. 520 BC; d. possibly 432 BC) was an astronomer of ancient Greece. He was a native of Tenedos. He is believed by ancient historians to have introduced the zodiac (beginning with Aries and Sagittarius) and the solar calendar. According to J. Webb, Cleostratus took his ideas from the Babylonians.