The Lower Danube marked the boundary between the empire and "Barbaricum" until Emperor Trajan decided to expand the frontiers over territories controlled by the Dacian Kingdom. He achieved his goal through two military campaigns, the second of which ended with the annihilation of the Dacian state and the establishment of the province of Dacia in 106. It included Oltenia and large portions of Banat, Transylvania, and Wallachia. Many colonists "from all over the Roman world" arrived and settled in the new province in the following decades.