The Parthians had begun to try to conquer as much of the eastern Seleucid empire as possible after 238 BCE, joined in this endeavor by the now independent province of Bactria.

The Seleucid king Antiochus II Theos was at the time too busy fighting a war against Ptolemaic Egypt and so the Seleucids had lost most of their territory east of Persia and Media.

Antiochus III, an ambitious Seleucid king who has a vision of reuniting Alexander the Great's empire under the Seleucid dynasty, launches a campaign in 209 BCE to regain control of the eastern provinces, and after defeating the Parthians in battle, he successfully regains control over the region.

The Parthians are forced to accept vassal status and now only control the land conforming to the former Seleucid province of Parthia.

However, Parthia's vassalage is only nominal at best and only because the Seleucid army is on their doorstep.

For his retaking of the eastern provinces and establishing the Seleucid borders as far east as they had been under Seleucus I Nicator, Antiochus is awarded the title ‘great’ by his nobles.

Antiochus establishes a magnificent system of vassal states but has had to recognize the independence of two kingdoms, that of the Parthians and that of the Greco-Bactrian ruler Euthydemus, which had been no more than satrapies.

Luckily for the Parthians, the Seleucid Empire has many enemies, and it will not be long before Antiochus leads his forces west to fight Ptolemaic Egypt and the rising Roman Republic.

A sideshow of the Punic war is the indecisive First Macedonian War in the Eastern Mediterranean and the Ionian Sea, during which conflict Philip V of Macedon again defeats the Aetolian League and Rome after the two ally against him in 211.

The war ends with two different peace treaties; one with the Aetolian League in 206 and one with Rome in 205 called the "Peace of Phoenice," which allows Philip to keep the land he had taken in Illyria.

This war is essentially a renewal of the Social War and ends in the same way, with the Aetolian League losing a second war to Philip V and Macedonia.

Philip, seeing his chance to defeat Rhodes, forms an alliance with Aetolian and Spartan pirates who begin raiding Rhodian ships.

Philip also forms an alliance with several important Cretan cities, such as Hierapynta and Olous.

With the Rhodian fleet and economy suffering from the depredations of the pirates, Philip believes his chance to crush Rhodes is at hand.

To help achieve his goal, he forms an alliance with the King of the Seleucid Empire, Antiochus the Great, against Ptolemy V of Egypt (the Seleucid Empire and Egypt are the other two Diadochi states).

Philip begins attacking the lands of Ptolemy and Rhodes's allies in Thrace and around the Sea of Marmara.

Rhodes and her allies Pergamon, Cyzicus, and Byzantium combine their fleets in 202 BCE and defeat Philip at the Battle of Chios.

Rome's first major military expedition into the Greek world meets with brilliant success, disrupting Hellenistic hegemony in the eastern Mediterranean.

Philip V loses all his territory outside Macedonia, and the victorious commander Flamininus establishes a Roman protectorate over the "liberated" Greek city-states.

Flamininus develops the policy of turning the cities, leagues, and kingdoms of the Hellenistic world into clients of Rome and of himself, a policy that will become the basis of Roman hegemony of the Mediterranean.

The fortunes of Greece and Rome for about the next five hundred years will henceforth be intertwined.

The Qin, under Shi Huangdi, have from about 200 BCE enlisted huge levies of laborers for the construction of extensive canal irrigation facilities in central China, and also to fill the gaps in the northern frontier walls built by earlier states, thus creating the Great Wall of China along the Mongolian border in the far north. (Little of this wall remains. Since then, the Great Wall has on and off been rebuilt, maintained, enhanced; the majority of the existing wall will be reconstructed during the Ming Dynasty.)

Liu Bang (or Liu Qi), a peasant warrior, leads a successful rebellion in opposition to the totalitarian Qin’s heavy requisitions for the military and public works projects.

The authority of Shi Huangdi's successor collapses in 206 BCE, and central power shifts to Liu Bang.

Liu Bang, after years of war with his rivals, establishes the Han dynasty and reunifies Central China in 202 BCE.

Establishing his capital at Chang'an, he inaugurates China’s Han Dynasty as Emperor Gaozu.

The fighting has left many areas of China depopulated and impoverished, and feudal lords continue to rebel while the Xiongnu make frequent incursions into northern Chinese territory.

The precarious state of the empire therefore forces the Han court to treat Nanyue initially with the utmost circumspection.

China’s new Han rulers force the northern invaders to retire behind the Great Wall and reduce Korea to vassal status.

Liu Bang, now Emperor Gaozu of Han, dies in 195.

His successor builds on the Qin’s stable and highly centralized government and a bureaucracy recruited by examination, giving rise to a new class of gentry-officials.

The Confucianist Han government, though structured along Qin lines, is somewhat more sensitive to the welfare of the peasantry.