|Millennium:||1st millennium BC|
|236 BC by topic|
Year 236 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Caudinus and Varus (or, less frequently, year 518 Ab urbe condita). The denomination 236 BC for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
- Antiochus Hierax, supported by his mother Laodice I, allies himself with the Galatians (Celts) and two other states that are traditional foes of the Seleucid kingdom. With the aid of these forces, he inflicts a crushing defeat on his older brother Seleucus II's army at Ancyra in Anatolia. Seleucus leaves the country beyond the Taurus Mountains to his brother and the other powers of the peninsula.
- Eratosthenes is appointed by King Ptolemy III Euergetes as head and third librarian of the Alexandrian library.
- Scipio Africanus, Roman general in the Second Punic War and statesman of the Roman Republic (approximate date) (d. 183 BC)