421 BC

Centuries:	6th century BC - 5th century BC - 4th century BC
Decades:	450s BC 440s BC 430s BC - 420s BC - 410s BC 400s BC 390s BC
Years:	424 BC 423 BC 422 BC - 421 BC - 420 BC 419 BC 418 BC

421 BC by topic
Politics
State leaders - Sovereign states
Birth and death categories
Births - Deaths
Establishments and disestablishments categories
Establishments - Disestablishments v • d • e

**421 BC in other calendars**
Gregorian calendar	421 BC
Ab urbe condita	333
Armenian calendar	N/A
Bahá'í calendar	-2264 – -2263
Buddhist calendar	124
Chinese calendar	2216/2276 ([[Sexagenary cycle\|]]年) — to — 2217/2277 ([[Sexagenary cycle\|]]年)
Ethiopian calendar	-428 – -427
Hebrew calendar	3340 – 3341
Hindu calendars
- Vikram Samvat	-365 – -364
- Shaka Samvat	N/A
- Kali Yuga	2681 – 2682
Holocene calendar	9580
Iranian calendar	1042 BP – 1041 BP
Islamic calendar	1074 BH – 1073 BH
Japanese calendar
- Imperial Year	Kōki 240 (皇紀240年)
- Jōmon Era	9580
Julian calendar	-375
Korean calendar	1913
Thai solar calendar	123
v • d • e

[edit] Events

Nicias, the leader of the aristocratic and peace party in Athens and Pleistoanax, King of Sparta, negotiate the Peace of Nicias between Athens and Sparta, which brings a temporary end to the Peloponnesian War. The essence of the Peace of Nicias is a return to the prewar situation: most wartime gains are to be returned. Seventeen representatives from each side swear an oath to uphold the treaty, which is meant to last for fifty years. All of Sparta's allies agree to sign the peace, except for the Boeotians, Corinth, Elis, and Megara.
Alcibiades engineers an anti-Spartan alliance between Athens and the democracies of Argos, Mantinea and Elis.

The city of Cumae, the most northerly of the Greek colonies in Italy, falls to the Samnites.

The construction of the Porch of the Maidens (the Caryatid Porch) commences at the Erechtheion which is part of the Acropolis in Athens.