Trajan attacked Dacia in the 101-2 period, defeated Decebalus, and exacted severe concessions on the losers. Almost immediately, the terms of the treaty were abused and a second war commenced in 105. This time Trajan laid siege to Sarmizegethusa and destroyed it. Decebalus committed suicide to avoid Roman capture.
Trajan made Dacia a Roman province extending its land as a deep wedge north from the Danube, a design intended to separate the local tribes and decrease their ability to organize together. This Dacian wedge survived until 270, when Aurelian abandoned the territory to conserve military resources.