Analysis of information sources in references of the Wikipedia article "Moesia" in Vietnamese language version.
Because the Dacians represented an obstacle against Roman expansion in the east, in the year 101 the emperor Trajan decided to begin a new campaign against them. The first war began on 25 March 101 and the Roman troops, consisting of four principal legions (X Gemina, XI Claudia, II Traiana Fortis, and XXX Ulpia Victrix), defeated the Dacians.
Although the Dacians had been defeated, the emperor postponed the final siege for the conquering of Sarmizegetuza because his armies needed reorganization. Trajan imposed on the Dacians very hard peace conditions: Decebalus had to renounce claim to some regions of his kingdom, including Banat, Tara Hategului, Oltenia, and Muntenia in the area southwest of Transylvania. He had also to surrender all the Roman deserters and all his war machines. At Rome, Trajan was received as a winner and he took the name of Dacicus, a title that appears on his coinage of this period. At the beginning of the year 103 A.D., there were minted coins with the inscription: IMP NERVA TRAIANVS AVG GER DACICVS.
However, during the years 103–105, Decebalus did not respect the peace conditions imposed by Trajan and the emperor then decided to destroy completely the Dacian kingdom and to conquer Sarmizegetuza.