0000's The 3rd Century BCE 200s BC
290s -

298-290: 3rd Samnite War creates coalition of Samnites, Etruscans, Celts, Sabines, Lucanians, Umbrians in opposition to Rome and her allies

297: Casander dies.

295: Roman victory at Sentinum leads to peace w/Etruscans

290: Peace w/Samnites, who were obliged to do military service.
280s -

287: Hortensian Law makes Plebiscites of the Roman plebian assembly (comitia tributa) binding without the ratification of the Senate or the Centuriate Assembly.
283: Ptolemy I dies.
282: Messina falls to Mamertine mercenaries.
281: Seleucus defeats and kills Lysimachus (age 80), in the plain of Coron, near Ipsus.

270s -
279: Vict of Pyrrhus at Ausculum with great losses (Pyrrhic victory) Plutarch's Pyrrhus
278: Celts (or Gauls) invade Macedonia and Thrace.
277: Antigonus Gonatus (grandson of Antipater) defeats Celts at Lysimacheia .
275 Romans defeat Pyrrhus at Beneventum
Livy's The History of Rome

260s -
264: Start of the First Punic War to 241. (Carthage vs. Rome)
264 Start of the First Punic War. (Carthage vs. Rome)
260: Roman ships defeat Carthaginian ships at Mylae.
250s -
256: Roman ships defeat Carthaginian ships at Cape Ecnomus.
243: Aratus captures Corinth.
Spartan King Agis IV - Plutarch's Agis
241: Roman ships defeat Carthaginian ships off the Aegadian Isles. First Punic War ends.
239: Antigonius dies of old age.
235: Attalus I defeats the Galatians.
227: Earthquake nearly destroys Rhodes.
219: Hannibal captures Saguntum in Spain.
218: Declaration of Second Punic War to 201 (Carthage vs.Rome)
217: Hannibal crosses Alps from Gaul into Italy.
216 Hannibal defeats Roman army at Cannae (worst Rom def in history, 50,000 out of 86,000 men lost).
214: Roman General Marcus Claudius Marcellus besieges Syracuse, which is allied with Carthage. War machines designed by Greek mathematician Archimedes devastate Roman war ships. The siege fails and the blockade begins.
212: Archimedes, the greatest inventor of antiquity, is killed while safeguarding a few scientific instruments, when Marcellus allows his Roman soldiers to loot the city of Syracuse.

202: Hannibal defeated at Zama by Scipio Africanus

1st Millennium BC 200s BC

Plutarch's Demetrius
Plutarch's Pyrrhus
Plutarch's Cleomenes
Plutarch's Aratus
Plutarch's Fabius
Plutarch's Marcellus
Plutarch's Agis