*The **conquest** of Dacia, 101–106 A. D.* In the third year of his rule Trajan undertook the conquest of Dacia, for Domitian’s agreement with Decebalus was regarded as a disgrace and the existence of a strong Dacian kingdom was a perpetual menace to the Danubian frontier. Decebalus was still king of the Dacians and proved himself a valiant opponent, but in two well-conducted campaigns (101–102 A. D.) Trajan forced him to sue for peace. He was obliged to give up his engines of war with the Roman engineers whom he had received from Domitian, to acknowledge Roman overlordship and render military service to Rome. Trajan built a permanent stone bridge across the Danube below the Iron Gates to secure communication with the northern bank, and returned to Rome to celebrate his victory with a triumph. But Decebalus was not content to remain as a Roman vassal and made preparations to recover his people’s independence. In 105 A. D. he opened hostilities by an invasion of Moesia. However, Trajan hurried to the scene, secured the support of the neighboring tribes, and in the following year entered Dacia. His victory was complete, the capital of Decebalus was captured, the king took his own life, and such of the Dacians as did not abandon their country were hunted down and exterminated. Dacia was made a Roman province, and was peopled with settlers from various parts of the empire, particularly from Asia Minor. The new province was of importance both on account of its gold mines and its position as a bulwark defending the provinces to the south of the Danube. To commemorate his Dacian wars, Trajan erected a stone column, one hundred feet high, in the new forum which bore his name. The column, which is still in place, is adorned with a spiral band of sculptured reliefs that vividly trace the course of the military operations. On other frontiers also Trajan strengthened or extended the boundaries of the empire. In 106 he annexed the kingdom of the Nabataean Arabs to the east of Palestine and Syria. From this was formed the province of Arabia. In Africa also the Romans occupied new territory, and secured it against Berber raids by creating new fortresses at Lambaesis and Timgad.