Trajan's Dacian Wars
Trajan's Dacian Wars produced one of the most striking monuments in the ancient world: a carved column standing in Rome that depicts two separate wars, thousands of soldiers, and the final moments of a king who chose death over capture. The column still stands today. But what drove the Roman Empire and the Dacian kingdom to fight twice in the span of five years, between 101 and 106 AD? What made Dacia so dangerous, so desirable, and ultimately so doomed? The answers lie in gold, iron, broken treaties, and the ambition of a new emperor who needed a war to prove himself.
Rome had been watching Dacia with unease since before Julius Caesar's time. Dacians defeated a Roman army at the Battle of Histria, and that memory did not fade quickly. By the time Emperor Trajan came to power, Dacia was no ordinary neighbor.
Researchers estimate that among many of Rome's other enemies, only about ten percent of warriors had access to swords, typically the nobility. Dacia was different. Its rich deposits of iron and copper fed a culture of metalworking, and a large proportion of Dacians owned swords. That single fact dramatically reduced the military edge Rome normally counted on.
Dacia could field an estimated 250,000 potential combatants. It had alliances with several neighboring peoples and maintained friendly relations with others Rome counted as enemies. Rome, at the time, had no firm defensive policy in the region and could not have sustained a prolonged defensive war. Trajan, an experienced soldier and tactician, withdrew troops from other borders to prepare the invasion, leaving those frontiers dangerously thin.
Adding fuel to the rivalry was money. Rome was suffering from economic strain, partly the result of a low gold content in its coinage, a policy that traced back to Emperor Nero. Rumors of Dacian gold and silver deposits had circulated for years, and they were confirmed. Those mineral riches made Dacia worth fighting for.
Before Trajan ever crossed the Danube, his predecessor Domitian had already negotiated a peace with the Dacian king Decebalus in 89 AD. Under that agreement, Rome paid Decebalus an annual subsidy of 8 million sesterces. Rome also provided craftsmen skilled in both peaceful and military trades, along with war machines meant to defend the empire's frontiers.
Decebalus used all of it to fortify his own kingdom instead. He rebuilt Dacian defenses, strengthened his army, and continued to oppose Rome even while maintaining a surface level of diplomatic contact. Roman dissatisfaction with the arrangement persisted and deepened.
When Trajan came to power, he was determined to correct what Domitian had left unresolved. The subsidy, the gifted engineers, the war machines, all of it had been turned against Rome. Trajan gained the blessing of the Senate and by 101 was ready to move. The first war was not a spontaneous response to a single provocation. It was the conclusion of a long calculation.
Trajan's opening campaign in 101 moved with notable speed and engineering ambition. His chief engineer, Apollodorus of Damascus, constructed a pontoon bridge across the Danube and cut a road directly through the river cliffs to allow the legions to advance. Two legionary columns drove straight toward the heart of Dacia, burning towns and villages as they went.
The Romans won at the Third Battle of Tapae and also at Adamclisi. In the winter of 101-102, a Roman army massed near what would become the city of Nicopolis ad Istrum, where the rivers Iatrus and Rositsa meet, and defeated an attack by the Sarmatian Roxolani, who were allied with the Dacians. The city took its name from that victory.
By 102, Decebalus could see that the Roman advance toward his capital at Sarmizegetusa could not be stopped. He chose peace. The terms were steep: he had to surrender territory and the engineers Domitian had provided, return equipment, accept Roman garrisons in Dacia, and agree not to cross the Danube.
A permanent stone bridge was also built across the Danube at Drobeta, designed by Apollodorus. It was probably the largest bridge of its era and for many centuries afterward. Its purpose was clear: to allow Roman forces to return quickly if needed. Decebalus accepted the terms, and within a few years began breaking them.
Peace lasted only briefly. Decebalus rebuilt his forces, stirred neighboring tribes against Rome, and began raiding Roman colonies across the Danube. He was also, according to the source, inciting revolt among tribes more broadly.
By 105, Trajan had assembled a second army at his Danube headquarters, probably at Drobeta. His force included contingents of Quadi, Marcomanni, Getae, and Iazyges. This second war proved harder than the first. Faced with numerous allied tribes, the Roman legions struggled to win a decisive engagement, and there was a second temporary peace before Rome pushed through again.
The Romans gradually dismantled the system of mountain fortresses protecting Sarmizegetusa. The final decisive battle came near the capital's walls, probably in the summer of 106. The legions II Adiutrix and IV Flavia Felix were present, along with a detachment from VI Ferrata.
The Dacians repelled the first Roman assault on the city. Then a treacherous local nobleman revealed the location of the water pipes supplying the capital. Roman forces destroyed them. Cut off from water and food, Sarmizegetusa fell and was razed.
Decebalus fled as the capital was taken. Roman cavalry pursued him. Rather than be captured and displayed in a Roman triumph, he took his own life.
The war did not end with his death. Fighting continued, and the last major battle took place at Porolissum, known today as Moigrad. But the most remarkable event of the aftermath came through betrayal. A confidant of Decebalus named Bicilis revealed to the Romans where the Dacian king had hidden his personal treasury. The gold and silver had been concealed in the river of Sargesia, also called the Sargetia. The historian Carcopino estimated the hoard at 165,500 kilograms of gold and 330,000 kilograms of silver.
That treasure, combined with the gold and silver mines of Dacia itself, gave Rome an extraordinary infusion of wealth. Estimates recorded in the source suggest the province of Dacia went on to contribute 700 million denarii per year to the Roman economy.
Trajan announced 123 days of celebrations across the empire. He also sent one hundred thousand male slaves back to Rome. To prevent future uprisings, two legions, XIII Gemina and V Macedonica, were permanently stationed in the new province.
Only the southern half of Dacia was formally annexed as a Roman province. The northern part remained outside direct Roman control but never coalesced into a new independent state.
The demographic transformation was sweeping. An ancient source quoted by the article recorded that Trajan transplanted people from across the Roman world to repopulate the country, because Decebalus's long war had exhausted its native population. Out of 3,000 personal names identified in the province of Dacia after the conquest, only 60 were of Dacian origin, while 2,200 were Roman. The remains of Roman mining activity are still visible at the site of Rosia Montana.
Those Dacians who remained outside the province, the so-called Free Dacians, continued to raid the new Roman territory. They allied with the Sarmatians and kept up pressure on Rome's eastern flank. Inside the province, the divided Dacian population mounted at least two rebellions against Roman authority. Trajan's victory was complete in military terms, but the region did not simply become quiet.
Trajan used the resources flowing from Dacia to finance extensive building projects in Rome. His prolific habit of attaching his name to those projects earned him the nickname Ivy, a reference to the plant that clings to everything it touches.
The most enduring monument of the two wars was not a building but a column. Trajan's Column was erected in Rome to commemorate the campaigns, and it depicts the wars in continuous carved relief running from base to top. It remains one of the most detailed visual records of Roman military operations that survives from antiquity. Apollodorus of Damascus, the engineer who built the pontoon bridge for the first war and the great stone bridge at Drobeta for the second, is generally credited as the designer of the column's base as well.
Common questions
When did Trajan's Dacian Wars take place?
Trajan's Dacian Wars were fought in two phases: the First Dacian War ran from 101 to 102 AD, and the Second Dacian War from 105 to 106 AD. Both campaigns were fought against the Dacian king Decebalus during the reign of Emperor Trajan.
Why did Rome fight Dacia under Trajan?
Rome attacked Dacia for several reasons: Dacian king Decebalus had violated a peace treaty made under Emperor Domitian in 89 AD, using Roman subsidies and engineers to strengthen Dacian defenses instead. Dacia also possessed rich gold and silver mines Rome needed, and Dacia could field an estimated 250,000 combatants, posing a direct military threat.
Who was Apollodorus of Damascus and what did he build for the Dacian Wars?
Apollodorus of Damascus was Trajan's chief military engineer. He built a pontoon bridge across the Danube for the first war, cut a road through the river cliffs, and designed the great stone bridge at Drobeta used during the second war. He is also generally associated with the construction of Trajan's Column in Rome.
How did Rome capture Sarmizegetusa during the Second Dacian War?
Roman forces besieged Sarmizegetusa in 106 AD with the legions II Adiutrix and IV Flavia Felix among the attacking units. After the Dacians repelled the first assault, a treacherous local nobleman revealed the location of the city's water pipes. The Romans destroyed them, cutting off the city's water and food supply, and Sarmizegetusa fell and was razed.
What happened to Decebalus at the end of the Dacian Wars?
Decebalus fled when Sarmizegetusa fell in 106 AD. Roman cavalry pursued him, and rather than be captured, he took his own life. His confidant Bicilis then revealed to Roman forces where Decebalus had hidden his treasury in the river Sargesia, a hoard estimated by the historian Carcopino at 165,500 kilograms of gold and 330,000 kilograms of silver.
What was the aftermath of Trajan's Dacian Wars for the province of Dacia?
Rome annexed the southern half of Dacia as a new province and settled it with colonists from across the empire. One hundred thousand male slaves were sent to Rome, and legions XIII Gemina and V Macedonica were permanently stationed in the province. The conquered territory went on to contribute an estimated 700 million denarii per year to the Roman economy. Of 3,000 personal names identified in the province, only 60 were of Dacian origin while 2,200 were Roman.
All sources
13 references cited across the entry
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- 3bookIn The Name of RomeAdrian Goldsworthy — Orion — 2004
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- 5journalTrajan's Conquest of DaciaEdward Togo Salmon — Johns Hopkins University Press — 1936
- 6encyclopediaDe Imperatoribus Romanis
- 7bookThe Dacian threat, 101-106 ADMichael Schmitz — Caeros Publishing — 2005
- 8journalGIS Analysis and Spatial Networking Patterns in Upland Ancient Warfare: The Roman Conquest of DaciaIoana A. Oltean et al. — January 2021
- 9journalConquest strategy and political discourse: new evidence for the conquest of Dacia from LiDAR analysis at Sarmizegetusa RegiaI. A. Oltean et al. — 2017
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