Early in the century, theRoman Empire attained its greatest expansion under the emperorTrajan, but after his death became primarily defensive for the rest of its history. Much prosperity took place throughout the empire at this time, ruled as it was by the "Five Good Emperors", a succession of well-received and able rulers. This period also saw the removal of theJews fromJerusalem during the reign ofHadrian afterBar Kokhba's revolt.
Although theHan dynasty ofChina was firmly cemented into power and extended its imperial influence intoCentral Asia during the first half of the century, by the second halfthere was widespread corruption andopen rebellion. This led to its decline, and in September 189, the Han generalDong Zhuo, after being summoned to the capital byHe Jin to help quell the corrupt and powerfuleunuch faction by serving as an intimidator to both them and theEmpress Dowager, marched his army intoLuoyang in light of He Jin's assassination and the subsequent slaughter of the eunuchs, taking over the capital and effectively becoming thede facto head of the government.
Warlords and government officials quickly took against himin a campaign that, while failing to put him down, compelled Dong Zhuo to shift the seat of imperial power further west toChang'an. As Dong Zhuo was killed in 192, the chaos in the wake of the collapse of centralized authority only continued, with various warlords attempting to vie for supremacy in order to establish or hold onto their authority within the decaying empire. Meanwhile, Dong Zhuo's former followersLi Jue andGuo Si were left to squabble amongst themselves, whileEmperor Xian himself fled and returned to the ravaged city of Luoyang. In 196, he was given refuge by the warlordCao Cao, who relocated him to the new capital city ofXu, from where he could control the emperor. Cao Cao would further exert his authority by defeating the powerful warlordYuan Shao at the decisiveBattle of Guandu in 200.
^Lightfoot, C.S. (1990). "Trajan's Parthian War and the Fourth-Century Perspective".The Journal of Roman Studies.80:115–126.doi:10.2307/300283.JSTOR300283.
Sidebottom, Harry (2005). "Roman Imperialism: The Changed Outward Trajectory of the Roman Empire".Historia: Zeitschrift für Alte Geschichte.54 (3):315–330.JSTOR4436777.