3rd century

The 3rd century is the period from 201 to 300 in accordance with the Julian calendar in the Christian/Common Era.

In this century, the Roman Empire sees a crisis, marking the beginning of Late Antiquity. In Persia, the Parthian Empire is succeeded by the Sassanid Empire.

In India, the Kushan Empire is replaced by the Gupta Empire. China is in the Three Kingdoms period. The Xiongnu form the Tiefu state under Liu Qubei. Korea is ruled by the Three Kingdoms of Korea. Japan enters the Kofun period.

In Sub-Saharan Africa, the Bantu expansion reaches Southern Africa.

In Pre-Columbian America, the Adena culture of the Ohio River valley declines in favor of the Hopewell culture. The Maya civilization enters its Classic Era.

Roman Empire

After the death of Commodus in the previous century the Roman Empire was plunged into a civil war. When the dust settled, Septimius Severus emerged as emperor, establishing the Severan dynasty. Unlike previous emperors, he openly used the army to back his authority, and paid them well to do so. The regime he created is known as the Military Monarchy as a result. The system fell apart in the 230s, giving way to a fifty-year period known as the Military Anarchy or the Crisis of the Third Century, where no fewer than twenty emperors held the reins of power, most for only a few months. The majority of these men were assassinated, or killed in battle, and the empire almost collapsed under the weight of the political upheaval, as well as the growing Persian threat in the east. Under its new Sassanid rulers, Persia had grown into a rival superpower, and the Romans would have to make drastic reforms in order to better prepare their state for a confrontation. These reforms were finally realized late in the century under the reign of Diocletian, one of them being to divide the empire into an eastern and western half, and have a separate ruler for each.

Events

* 208: the Chinese naval Battle of Red Cliffs occurs
* 212: Constitutio Antoniniana grants citizenship to all free Roman men
* 212–216: Baths of Caracalla
* 220: The Han Dynasty comes to an end with establish of the Wei Dynasty.
* 230–232: Sassanid dynasty of Persia launches a war to reconquer lost lands in the Roman east
* 235–284: Crisis of the Third Century shakes Roman Empire
* 250–538: Kofun era, the first part of the Yamato period in Japan
* 258: Valerian's Massacre of Christians
* 260: Roman Emperor Valerian I is taken captive by Shapur I of Persia
* 184–280: Period of the Three Kingdoms in China
* 280–420: Jin Dynasty (265-420) of China
* Sarnath becomes a center of Buddhist arts in India
* Diffusion of maize as a food crop from Mexico into North America begins
* The Kingdom of Funan reaches its zenith under the rule of Fan Shih-man
* The Goths move from Gothiscandza to Ukraine, giving birth to the Chernyakhov culture

ignificant persons

* Clement of Alexandria
* Diocletian, Roman emperor
* Diophantus of Alexandria, wrote "Arithmetica"
* Hippolytus, considered first Antipope
* Liu Hui, Chinese mathematician
* Mani (prophet), founder of Manichaeism
* Origen
* Nagarjuna
* Pappus of Alexandria, Greek mathematician
* Plotinus, founder of Neoplatonism
* Tertullian, sometimes called "father of Latin church"
* Wang Pi, Taoist
* M. Sattonius Iucundus, restorer of the Thermae in Heerlen
* Zhuge Liang, known as the greatest strategist during the period of the Three Kingdoms
* Liu Bei, founding emperor of the Kingdom of Shu
* Cao Cao, founding emperor of the Kingdom of Wei

Inventions, discoveries, introductions

* A primitive form of eyeglasses were developed for a nearsighted princess in Syria.
* The South Pointing Chariot invented by Ma Jun, a wheeled mechanical device that acts as a directional compass

Decades and years