Hadean
The Hadean () is a geologic eon of the Earth pre-dating the Archean. It began with the formation of the Earth about 4.6 billion years ago and ended, as defined by the ICS, 4 billion years ago. , the ICS describes its status as ""informal"". Geologist Preston Cloud coined the term in 1972, originally to label the period before the earliest-known rocks on Earth. W. Brian Harland later coined an almost synonymous term, the "Priscoan period", from "priscus", the Latin word for "ancient". Other, older texts simply refer to the eon as the Pre-Archean.
Fifth-century Athens
Fifth-century Athens is the Greek city-state of Athens in the time from 480–404 BC. This was a period of Athenian political hegemony, economic growth and cultural flourishing formerly known as the Golden Age of Athens with the later part The Age of Pericles. The period began in 478 BC after defeat of the Persian invasion, when an Athenian-led coalition of city-states, known as the Delian League, confronted the Persians to keep the liberated Asian Greek cities free. After peace was made with Persia in the mid 5th century BC, what started as an alliance of independent city-states became an Athenian empire when Athens abandoned the pretense of parity among its allies and relocated the Delian League treasury from Delos to Athens, where it funded the building of the Athenian Acropolis and put half its population on the public payroll and maintained dominating naval power in the Greek world. With the empire's funds, military dominance and its political fortunes guided by statesman and orator Pericles, Athens produced some of the most influential and enduring cultural artifacts of the Western tradition. The playwrights Aeschylus, Sophocles and Euripides all lived and worked in 5th century BC Athens, as did the historians Herodotus and Thucydides, the physician Hippocrates, and the philosophers Plato and Socrates. Athens' patron goddess was Athena, from whom they derived the name.