The region of Wu, in the south of the Yangtze River surrounding Nanjing, had during the decline of the Han dynasty been under the control of the warlord Sun Quan, who had succeeded his brother Sun Ce as the lord over the Wu region paying nominal allegiance to Emperor Xian of Han (who was, at that point, under the control of the warlord Cao Cao).

Sun Quan, unlike his competitors, lacked sufficient ambition ambition to be Emperor of China, and had ruled from 200 to 222 as Wu Wang (King/Prince of Wu).

After Cao Pi of the Kingdom of Wei and Liu Bei of the Kingdom of Shu each declared themselves to be the Emperor, Sun Quan had decided to follow suit in 229, claiming to have founded the Wu Dynasty.

Formally Emperor Da of the Wu Dynasty, one of the Three Kingdoms competing for control of China after the fall of the Han Dynasty, he dies in 252 and is succeeded by Sun Liang, his youngest son.

Southern China, regarded in early history as a barbaric "jungle", has developed under the rule of Eastern Wu into one of the commercial, cultural, and political centers of China.

The development of Southern China will surpass that of the north within five centuries, during the Five Dynasties and Ten States period.

The achievements of Wu mark the beginning of the cultural and political division between Northern and Southern China that will repeatedly appear in Chinese history well into modernity.

…imposes his son Artavasdos on Armenia, …

…attacks Mesopotamia, and …

…takes Nisibis from the Romans.

Shapur I soon resumes his attacks against a Roman Empire debilitated by Germanic invasions and a series of short-term emperors.

He reconquers Armenia, and incites Anak the Parthian, an Arsacid Prince and said to be related to the Arsacid Kings of Armenia, to murder the new king of Armenia, Khosrov II, promising to return his own domain as a reward.

Khosrov II is the son of Tiridates II, King of Armenia by an unnamed mother, and follows his father on the Armenian throne.

He is the namesake of his paternal grandfather Khosrov I and the Parthian monarchs: Osroes I and Osroes II.

In Armenian sources, Khosrov II is often confused with his grandfather Khosrov I.

Little is known on his life prior to becoming Armenian King.

From 226 until 238, Tiridates II had been in military conflict with Ardashir I, the first king and founder of the Sassanid Empire.

Ardashir I had wanted to expand his empire, which included conquering Armenia.

Khosrov II’s father had put up a stubborn resistance against Ardashir I.

After twelve years of fighting, although Tiridates II was defeated by Ardashir I, Ardashir I had withdrawn his army and left Armenia.

Khosrov II had participated in his father’s military campaigns against Ardashir I and Ardashir I had been alarmed by the victories of Tiridates II and Khosrov II against him.

Tiridates II dies in 252 and Khosrov II succeeds his father as King of Armenia and makes his capital at Vagharshapat.

From an unknown wife, Khosrov II has known two children: a daughter, called Khosrovidukht and a son called Tiridates III.

Anak, winning Khosrov II’s trust, treacherously murders Khosrov II with his wife in Vagharshapat; in return, the outraged Armenian nobles slay Anak with his entire family.

Shapur then appoints his son Hormizd I as the “Great King of Armenia”.

With Armenia subjugated, Georgia submits to the Sassanian Empire and falls under the supervision of a Sassanian official.

The Sassanians' northern borders are thus secured.

The third century has been a time of crisis for the Legio III Augusta, which has been stationed at Lambaesis in Numidia for more than two centuries, since the reign of Hadrian, guarding the province from the Berber tribes.

First, it had suffered heavy losses in a war against a desert tribe, having to receive reinforcements from the recently disbanded Legio III Gallica.

The legion had suppressed the revolt of Gordian I and Gordian II in 238, the Year of the Six Emperors,  but had been disbanded by their successor Gordian III.

Valerian reconstitutes the Legio III Augusta in 252 with troops coming from Raetia and Noricum, and gives it the cognomen Iterum Pia Iterum Vindex (Again faithful, again avenger).

The purpose of this reconstitution is to wage a war against a federation of Berber tribes that threaten the empire.

The Goths break the peace treaty, renewing their attacks early in 253.

The army is not pleased with the emperor and when Marcus Aemilius Aemilianus, who had replaced Gallus as governor of Moesia Superior and Pannonia, takes the initiative of battle and defeats the Goths in midyear, the soldiers proclaim him emperor.

The Crimean Goths and the Heruls, a Germanic people from northern Europe, dare to venture on the seas beginning in 253, ravaging the shores of the Black Sea in violation of a treaty signed with Rome.

Shapur defeats a large Roman force of sixty thousand in 253 at the Battle of Barbalissos, only known through Shapur's inscription at Naqš-e Rostam.

This victory leaves the Roman east open to attack and leads to the eventual capture of Antioch and Dura Europos three years later.

Shapur burns and ravages the Roman province of Syria and all its dependencies.

The Goths move south to ravage the Aegean island ports, as well as several mainland Greek towns.