210s BC

• Following the defection of one of Ptolemy IV's leading commanders, Egypt's Syrian territories are seriously threatened by Antiochus III, thus initiating the Fourth Syrian War. When the Seleucid ruler captures the important eastern Mediterranean sea ports of Seleucia-in-Pieria, Tyre, and Ptolemais, Ptolemy IV's advisor, Sosibius, and the Ptolemaic court enter into delaying negotiations with the enemy, while the Ptolemaic army is reorganized and intensively drilled.
• The former King of Sparta, Cleomenes III, escapes from his Egyptian prison and, after failing to raise a revolt in Alexandria, takes his own life.

• The Romans extend their area of domination around the head of the Adriatic Sea as far as the peninsula of Histria by the conquest of peoples who dwell to the east of the Veneti. Thus, with the exception of Liguria and the upper valley of the Po River, all Italy south of the Alps is brought within the Roman sphere.

• Hannibal lays siege to Saguntum[1] thus initiating the Second Punic War between Carthage and Rome. Saguntum is an independent Iberian Peninsula city south of the Ebro River. In the treaty between Rome and Carthage concluded in 226 BC, the Ebro had been set as the northern limit of Carthaginian influence in the Iberian Peninsula. Saguntum is south of the Ebro, but the Romans have "friendship" with the city and regard the Carthaginian attack on it as an act of war. The siege of Saguntum lasts eight months, and in it Hannibal is severely wounded. The Romans, who send envoys to Carthage in protest, demand the surrender of Hannibal.

• The Roman Senate sends the consul Lucius Aemilius Paullus to Illyria with an army. On discovering Rome's intent, the Illyrian leader Demetrius of Pharos puts to death those Illyrians who oppose his rule, fortifies Dimale and goes to Pharos. After a seven-day siege by the Roman fleet under Lucius Aemilius Paulus, Dimale is taken by direct assault. From Dimale, the Roman navy heads to Pharos, where the Roman forces rout the Illyrians. Demetrius flees to Macedonia, where he becomes a trusted councilor at the court of King Philip V.
• The Cretan city of Kydonia joins the Aetolian alliance.[2]

• Qin Shi Huang orders his generals to capture present-day Guangdong and Guangxi.

== {{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}} == {{trim|{{transcluded section|{{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}}}} {{#section-h::{{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}}|Events}}}} == {{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}} == {{trim|{{transcluded section|{{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}}}} {{#section-h::{{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}}|Events}}}} == {{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}} == {{trim|{{transcluded section|{{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}}}} {{#section-h::{{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}}|Events}}}} == {{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}} == {{trim|{{transcluded section|{{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}}}} {{#section-h::{{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}}|Events}}}} == {{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}} == {{trim|{{transcluded section|{{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}}}} {{#section-h::{{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}}|Events}}}} == {{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}} == {{trim|{{transcluded section|{{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}}}} {{#section-h::{{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}}|Events}}}} == {{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}} == {{trim|{{transcluded section|{{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}}}} {{#section-h::{{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}}|Events}}}} == {{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}} == {{trim|{{transcluded section|{{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}}}} {{#section-h::{{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}}|Events}}}} == {{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}} == {{trim|{{transcluded section|{{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}}}} {{#section-h::{{dr|y|y|{{1x|-}}{{{year}}}0|{{1x|-}}{{{1}}}|na}}|Events}}}}

== {{ucfirst:{{{1}}}}} == {{preprocess|{{((}}transcluding articles {{!}} {{for loop|{{!}}|call=Year article|pc1n=1|pc1v={{{decade}}}0|pv=2|-9|-8|-7|-6|-5|-4|-3|-2|-1}} {{!}} {{#ifeq:{{{decade}}}|-0|{{void|There is no BC year 0}}|{{Year article|{{{decade}}}0}}}} {{))}}}} {{for loop| |call=Transclude {{{1}}}|{{{decade}}}9|{{{decade}}}8|{{{decade}}}7|{{{decade}}}6|{{{decade}}}5|{{{decade}}}4|{{{decade}}}3|{{{decade}}}2|{{{decade}}}1}} {{#ifeq:{{{decade}}}|-0|{{void|There is no BC year 0}}| {{Transclude {{{1}}}|{{{decade}}}0}} }} == {{ucfirst:{{{1}}}}} == {{preprocess|{{((}}transcluding articles {{!}} {{for loop|{{!}}|call=Year article|pc1n=1|pc1v={{{decade}}}0|pv=2|-9|-8|-7|-6|-5|-4|-3|-2|-1}} {{!}} {{#ifeq:{{{decade}}}|-0|{{void|There is no BC year 0}}|{{Year article|{{{decade}}}0}}}} {{))}}}} {{for loop| |call=Transclude {{{1}}}|{{{decade}}}9|{{{decade}}}8|{{{decade}}}7|{{{decade}}}6|{{{decade}}}5|{{{decade}}}4|{{{decade}}}3|{{{decade}}}2|{{{decade}}}1}} {{#ifeq:{{{decade}}}|-0|{{void|There is no BC year 0}}| {{Transclude {{{1}}}|{{{decade}}}0}} }}