Seleucus Nicator builds Antioch, which he makes the capital of his kingdom of Syria.
299. Rome engages in the Third Samnite War, which becomes one of extermination, but the Samnites bravely resist in their mountain holds.
295. Pyrrhus, King of Epirus, espouses Antigone of the house of Ptolemy; he returns to his dominions, out of which he had been driven by the Molossi.
The Samnites, Etruscans, Umbrians, and Gauls unite against Rome. Q. Fabius Rullianus and P. Decimo Mus defeat the Samnites and Gauls at Sentinum.
Demetrius Poliorcetes retakes Athens; Lysimachus and Ptolemy deprive him of all he possesses.
294. The Macedonian throne is seized by Demetrius Poliorcetes; by violence or treachery the sons of Cassander are slain.
293. Many towns of the Samnites are so utterly destroyed by the Romans that their sites are unknown; a portion of the spoil is cast into a brazen colossus, and placed in front of the Roman Capitol.
The Roman census is 272,308 citizens.
The first sun-dial at Rome is placed on the temple of Quirinus.
290. The end of the Third Samnite War, which results in the submission of the Samnites to Rome.