Trajan's Dacian Wars

Trajan's Dacian Wars
Part of the Dacian Wars

Image of Victoria used to separate the two wars on Trajan's Column
Date101–102 and 105–106
Location
Ancient Dacia
Result Roman victory
Territorial
changes
Roman Empire annexes Dacia west of Siret river
Iazyge client kingdom set up in Banat and Oltenia
Belligerents
Dacia
Roxolani
Buri
Bastarnae
Roman Empire
Iazyges
Commanders and leaders
Decebalus  Trajan
Units involved
Dacian army
Strength
200,000 Dacians
Germanic and Sarmatian allies
16 legions (between 150,000 and 175,000 infantry + auxiliary)
Casualties and losses
Heavy
500,000 prisoners
Unknown

Trajan's Dacian Wars (101–102, 105–106) were two military campaigns fought between the Roman Empire and the Dacians under King Decebalus during the reign of Emperor Trajan. The conflicts stemmed from repeated Dacian incursions into the province of Moesia and from Rome's growing need for resources. Discontent with the treaty Domitian had concluded with Decebalus in 89 CE persisted, and Trajan, keen to assert himself as a soldier-emperor, took the opportunity to reassert Roman authority.

Trajan's First Dacian War began in 101 CE, when the emperor led a major offensive across the Danube using a pontoon bridge constructed by his engineer Apollodorus of Damascus, who also cut a road through the river cliffs. The Romans won a series of victories, including at Tapae and Adamclisi. Before Trajan could capture the Dacian capital, Sarmizegetusa, Decebalus sought peace. The treaty forced him to surrender territory and engineers provided by Domitian, return equipment, accept Roman garrisons, and refrain from crossing the Danube.

Within a few years Decebalus broke the agreement, rebuilding his forces, stirring neighboring tribes, and raiding Roman territory. In 105, Trajan launched the Second Dacian War, this time crossing on the great stone bridge at Drobeta, also designed by Apollodorus. Roman legions advanced north and destroyed Dacian fortresses, eventually besieging Sarmizegetusa. The Romans cut its water supply, and the city fell in 106. Decebalus fled but committed suicide to avoid capture, and his treasure was seized by Roman forces.

Rome annexed part of Dacia as a new province, settled with colonists from across the empire and secured with permanent garrisons. The conquest brought control of rich gold and silver mines, which strengthened the imperial treasury. Trajan celebrated with a triumph in Rome, accompanied by public feasts and games that lasted more than four months. The victory was commemorated by Trajan's Column, which depicts the wars in detail, and the influx of resources helped finance Trajan's extensive building projects in Rome.