Year 423 BC was a year of the pre-Julian Roman calendar

Roman calendar

The Roman calendar changed its form several times in the time between the founding of Rome and the fall of the Roman Empire. This article generally discusses the early Roman or pre-Julian calendars...

. At the time, it was known as the Year of the Consulship of Atratinus and Ambustus (or, less frequently, year 331 Ab urbe condita

Ab urbe condita

Ab urbe condita is Latin for "from the founding of the City ", traditionally set in 753 BC. AUC is a year-numbering system used by some ancient Roman historians to identify particular Roman years...

). The denomination 423 BC for this year has been used since the early medieval period, when the Anno Domini

Anno Domini

and Before Christ are designations used to label or number years used with the Julian and Gregorian calendars....

 calendar era

Calendar era

A calendar era is the year numbering system used by a calendar. For example, the Gregorian calendar numbers its years in the Western Christian era . The instant, date, or year from which time is marked is called the epoch of the era...

 became the prevalent method in Europe for naming years.

Persian empire

• Ochus, satrap
  Satrap
  Satrap was the name given to the governors of the provinces of the ancient Median and Achaemenid Empires and in several of their successors, such as the Sassanid Empire and the Hellenistic empires....
  
   of Hyrcania
  Hyrcania
  Hyrcania was the name of a satrapy located in the territories of present day Gilan, Golestan, Mazandaran and part of Turkmenistan, lands south of the Caspian Sea. To the Greeks, the Caspian Sea was the "Hyrcanian Sea".-Etymology:...
  
   and son of Artaxerxes I and a Babylonian concubine, seizes the Persian throne from his half brother Secydianus (or Sogdianus), whom he has executed. The new king rules as Darius II
  Darius II
  Darius II , was king of the Persian Empire from 423 BC to 405 BC.Artaxerxes I, who died on December 25, 424 BC, was followed by his son Xerxes II. After a month and a half Xerxes II was murdered by his brother Secydianus or Sogdianus...
  
  .

Greece

• The Athenian
  Athens
  Athens , is the capital and largest city of Greece. Athens dominates the Attica region and is one of the world's oldest cities, as its recorded history spans around 3,400 years. Classical Athens was a powerful city-state...
  
   general, Laches
  Laches (person)
  Laches was an Athenian aristocrat and general during the Peloponnesian War. His date of birth is unknown, but Plato asserts, not implausibly, that he was distinctly older than Socrates, who was born around 470 BC.In 427 BCE, Laches and Charoeades were sent to Sicily with a fleet of 20 ships in...
  
  , successfully moves in the Athenian Assembly for an armistice with Sparta
  Sparta
  Sparta or Lacedaemon, was a prominent city-state in ancient Greece, situated on the banks of the River Eurotas in Laconia, in south-eastern Peloponnese. It emerged as a political entity around the 10th century BC, when the invading Dorians subjugated the local, non-Dorian population. From c...
  
   to check the progress of Sparta's most effective general, Brasidas
  Brasidas
  Brasidas was a Spartan officer during the first decade of the Peloponnesian War.He was the son of Tellis and Argileonis, and won his first laurels by the relief of Methone, which was besieged by the Athenians . During the following year he seems to have been eponymous ephor Brasidas (died 422...
  
  . However, the "Truce of Laches" has little impact on Brasidas and collapses within a year.
• Brasidas ignores the proposed year-long truce and proceeds to take Scione
  Scione
  Scione was an ancient Greek city in Pallene, the westernmost headland of Chalcidice, on the southern coast east of the modern town of Nea Skioni....
  
   and Mende
  Mende (Greece)
  Mende was an ancient Greek city located in the western coast of Pallene peninsula in Chalkidiki facing the coast of Pieria across the narrow Thermaic Gulf near the modern town of Kalandra.- Ancient History :...
  
   in the hope of reaching Athens and freeing Spartan prisoners. Athens sends reinforcements under Nicias
  Nicias
  Nicias or Nikias was an Athenian politician and general during the period of the Peloponnesian War. Nicias was a member of the Athenian aristocracy because he had inherited a large fortune from his father, which was invested into the silver mines around Attica's Mt. Laurium...
  
   who retakes Mende.

Drama

• Aristophanes
  Aristophanes
  Aristophanes , son of Philippus, of the deme Cydathenaus, was a comic playwright of ancient Athens. Eleven of his forty plays survive virtually complete...
  
  ' play The Clouds
  The Clouds
  The Clouds is a comedy written by the celebrated playwright Aristophanes lampooning intellectual fashions in classical Athens. It was originally produced at the City Dionysia in 423 BC and it was not well received, coming last of the three plays competing at the festival that year. It was revised...
  
   is performed as is Sophocles
  Sophocles
  Sophocles is one of three ancient Greek tragedians whose plays have survived. His first plays were written later than those of Aeschylus, and earlier than or contemporary with those of Euripides...
  
  ' play Maidens of Trachi and The Putine (The Bottle), by Cratinus
  Cratinus
  Cratinus , Athenian comic poet of the Old Comedy.-Life:Cratinus was victorious six times at the City Dionysia, first probably in the mid- to late 450s BCE , and three times at the Lenaia, first probably in the early 430s...
  
  .

Deaths

• Sogdianus
  Sogdianus of Persia
  Sogdianus , died 423 BC, king of Persia . He was an obscure historical figure known primarily from the writings of Ctesias. He was reportedly an illegitimate son of Artaxerxes I by his concubine Alogyne of Babylon....
  
  , King of Persia
  Achaemenid Empire
  The Achaemenid Empire , sometimes known as First Persian Empire and/or Persian Empire, was founded in the 6th century BCE by Cyrus the Great who overthrew the Median confederation...
  
  (assassinated)