In 89 AD, the Roman Empire signed a treaty with King Decebalus of Dacia. This agreement included an annual subsidy of 8 million sesterces and provided craftsmen to help build Roman defenses. Instead of securing peace, Decebalus used these resources to fortify his own kingdom against Rome. The Dacian king continued to oppose Roman authority despite diplomatic efforts from Emperor Domitian. By the early second century, Rome faced economic difficulties due to military invasions across Europe. Emperor Nero had previously reduced the gold content in Roman currency, creating financial instability. Rumors of rich Dacian gold mines inflamed tensions further. Unlike other barbarian tribes where only nobility owned swords, most Dacians possessed weapons. Researchers estimate that 250,000 potential combatants lived within Dacia. This large fighting force threatened Roman borders along the Danube River. Trajan withdrew troops from other frontiers to prepare for this specific threat. The new emperor was an experienced soldier who understood the danger posed by an unbowed and unbroken neighbor.
First War Campaigns
Trajan launched his first offensive into Dacia in 101 CE after receiving Senate approval. Two legionary columns marched directly toward the heart of the enemy territory. Roman forces burned towns and villages as they advanced northward. At the Third Battle of Tapae, the Romans defeated a major Dacian army. During the winter of 101, 2, the Roman army gathered near Nicopolis ad Istrum at the junction of the Iatrus and Rositsa rivers. They prepared to face attacks from the Sarmatian Roxolani tribe which allied with the Dacians. A Roman victory there led to the city being named Nicopolis. Before capturing the capital Sarmizegetusa, Decebalus sought peace terms. The resulting treaty forced him to surrender territory and return equipment provided by Domitian. Roman garrisons were established while Decebalus agreed not to cross the Danube again. Apollodorus of Damascus designed a pontoon bridge across the river to assist future legions. This engineering feat allowed rapid movement of troops if war resumed. However, Decebalus soon broke the agreement by rebuilding fortresses using the very craftsmen Rome had sent.