3rdcentury

The 3rd century CE, spanning roughly 201 to 300, was a period of considerable instability and change across several regions. In the Roman Empire, a long crisis saw frequent changes of ruler, military incursions, and economic strain, while in East Asia the collapse of the Western Han led to the Three Kingdoms and the subsequent Jin unification. These upheavals coincided with the emergence of new powers and reform efforts that would shape late antiquity.

In the Roman world, the Crisis of the Third Century (235–284) weakened central authority. Breakaway states such as the Gallic Empire and Palmyra challenged imperial sovereignty, and external pressures from Germanic and Persian forces strained frontiers. Diocletian (r. 284–305) implemented wide-ranging reforms, reorganizing provincial governance, expanding the army, and introducing the tetrarchy to stabilize succession, while pursuing economic measures to restore fiscal health.

In Asia, the late Han gave way to the Three Kingdoms (Wei, Shu, Wu) in China, with the Jin dynasty unifying the north by 280 but soon facing its own turmoil. In the Near East, the Sassanid Dynasty supplanted Parthia in 224 CE, creating a durable Persian state that would rival Rome. Trade routes—Silk Road and Indian Ocean networks—facilitated cultural and commercial exchange across Eurasia, setting the stage for the transitions of late antiquity.