Trajan marches from Armenia to Mesopotamia following his successful Roman military campaign against Parthia in present-day Iraq, and in 116 establishes the new Roman province of Assyria, one of three provinces (with Armenia and Mesopotamia) he has created.
Coins are issued announcing that Armenia and Mesopotamia have been put under the authority of the Roman people.
Despite Rome's military victory, Trajan's new province is plagued with difficulties from the start.
A Parthian prince named Sanatruces, the son of Mithridates IV (mentioned as an ephemeral Parthian king in CE 115 by sixth-century writer John Malalas, in his Chronographia), organizes an armed revolt by the natives in the new Roman provinces.
Roman garrisons in Assyria and Mesopotamia are driven from their posts, and a Roman general is killed as his army tries unsuccessfully to stop the rebellion.
While many sources cite the creation of a province named Assyria during Trajan's Parthian campaign, some disagreement exists regarding its exact location.
Theodore Mommsen wrote that it was located north of the Roman Mesopotamia province, stretching into western Persia (in an area called Media Atropatene) in present northwestern Iran, but some modern scholars argue that the Assyria Provincia was located between the Tigris and Euphrates Rivers, in present-day central Iraq, a location that is corroborated by the text of the fourth-century Roman historian Festus.
However, other sources contend that the province was located near Armenia and east of the Tigris, in a region formerly known as Adiabene, which had long before been a Neo-Assyrian kingdom.
In early 116, however, Trajan began to toy with the conquest of the whole of Mesopotamia, an overambitious goal that will eventually backfire on the results of his entire campaign: One Roman division crosses the Tigris into Adiabene, sweeping south and capturing the fortress of Adenystrae (location most uncertain), the principle stronghold of Adiabene’s ruler Mebarsapes, forcing Mebarsapes to flee; …
