3rd century
The 3rd century AD was the period from 201 (CCI) to 300 (CCC).

In this century, the Roman Empire saw a crisis, starting with the assassination of the Roman Emperor Severus Alexander in 235, plunging the empire into a period of economic troubles, barbarian incursions, political upheavals, civil wars, and the split of the Roman Empire through the Gallic Empire in the west and the Palmyrene Empire in the east, which all together threatened to destroy the Roman Empire in its entirety, but the reconquests of the seceded territories by Emperor Aurelian and the stabilization period under Emperor Diocletian due to the administrative strengthening of the empire caused an end to the crisis by 284. This crisis would also mark the beginning of Late Antiquity.

In Persia, the Parthian Empire was succeeded by the Sassanid Empire in 224 after Ardashir I defeated and killed Artabanus V during the Battle of Hormozdgan. The Sassanids then went on to subjugate many of the western portions of the declining Kushan Empire.

In China, the chaos that had been raging since 189 would ultimately continue to persist with the decisive defeat of Cao Cao at the Battle of Red Cliffs in 208, which would increasingly end the hopes of unification and lead to the tripartite division of China into three main empires; Shu, Wu, and Wei, colloquially known as the Three Kingdoms period, which started in 220 with the formal abdication of Emperor Xian of Han to Cao Cao's son, Cao Pi, thereby founding Wei, which would go on to conquer Shu in 263, but would ultimately be united again under the Jin dynasty, headed by the Sima clan, who would usurp Wei in 266, and conquer Wu in 280.

In India, the Gupta Empire was on the rise towards the end of the century.

Korea was ruled by the Three Kingdoms of Korea. Japan entered the Kofun period. The Xiongnu formed the Tiefu state under Liu Qubei. The Southeast Asian mainland was mostly dominated by Funan; the first kingdom of the Khmer people (Cambodians).

At about this time in Sub-Saharan Africa, the Bantu expansion reached Southern Africa.

In Pre-Columbian America, the Adena culture of the Ohio River valley declined in favor of the Hopewell culture. The Maya civilization entered its Classic Era.
Q30387
201
TIME
Q38918
CCI
Concept
Q25641
300
TIME
Q38918
CCC
Concept
Q2277
Roman Empire
LOC
Q329838
crisis
TIME
Q1769
Severus Alexander
PER
Q273025
Gallic Empire
LOC
Q877875
Palmyrene Empire
LOC
Q46780
Aurelian
PER
Q43107
Diocletian
PER
Q217050
Late Antiquity
TIME
Q794
Persia
LOC
Q1986139
Parthian Empire
LOC
Q83891
Sassanid Empire
LOC
Q371319
Ardashir I
PER
Q316067
Artabanus V
PER
Q2887977
Battle of Hormozdgan
EVE
Q25979
Kushan Empire
LOC
Q82972
China
ORG
Q116123
chaos
Concept
Q204077
Cao Cao
Concept
Q830059
Battle of Red Cliffs
EVE
Q320925
Shu
MEDIA
Q274488
Wu
LOC
Q320930
Wei
MEDIA
Q185043
Three Kingdoms
LOC
Q7316
Emperor Xian of Han
PER
Q313333
Cao Pi
PER
Q1196063
conquer Shu
PER
Q7352
Jin dynasty
TIME
Q7356
Sima clan
PER
Q1151096
conquer Wu
PER
Q60140
India
LOC
Q11774
Gupta Empire
LOC
Q18097
Korea
LOC
Q165292
Three Kingdoms of Korea
MEDIA
Q17
Japan
LOC
Q459939
Kofun period
Concept
Q188836
Xiongnu
MEDIA
Q546282
Tiefu
MEDIA
Q3273270
Liu Qubei
PER
Q867782
Funan
LOC
Q201028
Khmer people
Concept
Q201028
Cambodians
Concept
Q132959
Sub-Saharan Africa
LOC
Q130251
Bantu expansion
Concept
Q27394
Southern Africa
LOC
Q4596701
Pre-Columbian America
UNK
Q355841
Adena culture
Concept
Q4915
Ohio River
LOC
Q1305793
Hopewell culture
MEDIA
Q28567
Maya civilization
Concept
None
Classic Era
UNK
Q8101
3rd century
Concept
+3^^http://www.w3.org/2001/XMLSchema#decimal
3
NUMBER
country of citizenship
child
time period
time period
time period
follows
country
part of
location