Both World precipitation and temperature were extremely high this year.
The Peloponnesian war continued.
Plague kills over one-third of the population of Athens. Morale in the city, where people are engaging in, among other things, excessive drinking and lewd behavior, is low.
Hippocrates, the famous Greek physician, pioneers the field of modern medicine circa 429 B.C. by studying anatomy and physiology and by expanding medical vocabulary to include words such as chronic, crisis, convalescence, relapse,and exacerbate.
Darius, the king of Persia, lost 300 ships under general Mardonius (Herodotus "Histories" book VI (Erato), Aeschylus "The Persians") in the waters around Mount Athos.
The battle of Spartolus of 429 BC was a costly Athenian defeat in a battle fought just outside the city of Spartolus in Chalcidice. s
The battle of Stratus (429 BC) was a Spartan defeat that ended a brief campaign designed to drive the Athenians out of Acarnania, the area to the north-west of the entrance to the Gulf of Corinth (Great Peloponnesian War)
The battle of Chalcis (429 BC) was the first of two Athenian naval victories won in the same year in the Gulf of Corinth that helped demonstrate their naval superiority in the early part of the Great Peloponnesian War.
The battle of Naupactus (429 BC) was a second Athenian naval victory won in a short period around the Gulf of Corinth, but was won by a very narrow margin and only after the narrow failure of a Peloponnesian plan to trap the entire Athenian fleet.
- The Great Peloponnesian War (431-404 BC)