The Middle East: 100–111 CE

Trajan’s Ambitious Eastern Expansion

The opening years of the second century CE see Roman Emperor Trajan decisively completing his conquest of Dacia, modern-day Romania, significantly enriching the Roman treasury with gold and silver from its mines. His attention then shifts decisively eastward, toward the persistent rivalry with the Parthian Empire. Trajan’s ambitions, reflecting Rome’s strategic interest in securing critical eastern trade routes and stabilizing its frontier, lead to an aggressive military posture against Parthia, marking one of the most significant chapters in Roman expansion into the Middle East.

The Roman frontier in the East, largely governed through indirect means—particularly via client kingdoms and allied states—has long buffered direct conflict with Parthia. However, Trajan's policy signals a more direct and confrontational approach, and his preparations foreshadow the extensive campaign to come. Rome seeks not just territorial expansion but to curb Parthian influence decisively, thereby securing lasting dominance over key areas such as Armenia, a strategically valuable region continually contested by the two great powers.

During this era, both empires experience internal complexities. The Parthian Empire, under Pacorus II and later Osroes I, contends with internal dissensions and regional aristocratic autonomy, factors that Trajan intends to exploit in his forthcoming eastern campaigns. Meanwhile, Roman provinces in the Middle East—particularly Syria, with cities like Antioch serving as crucial logistical and administrative hubs—are steadily strengthened to support Trajan’s eastern ambitions.

Thus, the years 100–111 CE lay the groundwork for what will soon become one of Rome's boldest imperial adventures, setting the stage for dramatic shifts in the geopolitical landscape of the Middle East.

…a second follows the river south, capturing Babylon; while …

…Trajan himself sails down the Euphrates, then drags his fleet overland into the Tigris, capturing Seleucia and finally, the Parthian capital of Ctesiphon.

Trajan continues southward to the Persian Gulf, receiving the submission of Athambelus, the ruler of Charax, whence he declares Babylon a new province of the Empire, sends the Senate a laureled letter declaring the war to be at a close and bemoaning that he is too old to go on any further and repeat the conquests of Alexander the Great.

A province of Assyria is also proclaimed, apparently covering the territory of Adiabene, as well as some measures seem to have been considered about the fiscal administration of the Indian trade.

However, as Trajan leaves the Persian Gulf for Babylon—where he intends to offer sacrifice to Alexander in the house where he had died in 323 BCE—a sudden outburst of Parthian resistance, led by a nephew of the Parthian king, Sanatruces, imperils Roman positions in Mesopotamia and Armenia, something Trajan seeks to deal with by forsaking direct Roman rule in Parthia proper, at least partially.

The emperor, after defeating a Parthian army in a battle where Sanatruces is killed and retaking Seleucia in 116, formally deposes the Parthian king Osroes I later in the year.

Parthamaspates, a pro-Roman son of Osroes who has spent much of his life in Roman exile, has accompanied Trajan on the latter's campaign to conquer Parthia.

Trajan had originally planned to annex Parthia as part of the Roman Empire, but ultimately decides instead to place Parthamaspates on his father's throne as a Roman client, doing so in 116.

That done, he retreats north in order to retain what he can of the new provinces of Armenia and Mesopotamia.

It is at this point that Trajan's health starts to fail him.

The fortress city of Hatra, on the Tigris in his rear, continues to hold out against repeated Roman assaults.

He is personally present at the siege and it is possible that he suffered a heat stroke while in the blazing heat.

Shortly afterwards, the Jews inside the Roman Empire rise up in rebellion once more, as do the people of Mesopotamia.

Trajan is forced to withdraw his army in order to put down the revolts.

Trajan sees it as simply a temporary setback, but he is destined never to command an army in the field again, turning his Eastern armies over to the high ranking legate and governor of Judaea, Lucius Quietus, who in early 116 had been in charge of the Roman division that had recovered Nisibis and Edessa from the rebels.

Trajan reconquers Nisibis (Nusaybin in Turkey), …

…Edessa, the capital of Osroene, a small Roman client state between Asia Minor and Syria, …

…Seleucia on the Tigris (Iraq), each of which houses large Jewish communities.

Osroes, following Roman withdrawal from the area, easily defeats Parthamaspates and reclaims the Parthian throne.

Trajan grows ill early in 117 and sets out to sail back to Italy.

His health declines throughout the spring and summer of the year, something publicly acknowledged by the fact that a bronze bust displayed at the time in the public baths of Ancyra show him clearly aged and emaciated.

By the time he reaches Selinus in Cilicia, which is afterwards called Trajanopolis, he suddenly dies from edema on August 9.

Some say that he had adopted Hadrian as his successor, but others that it was his wife Pompeia Plotina who hired someone to impersonate him after he had died.