 However, Decebalus in 105 undertook an invasion against Roman territory by attempting to stir up some of the tribes north of the river against the empire.Trajan took to the field again and after building with the design of Apollodorus of Damascus his massive bridge over the Danube, he conquered part of Dacia in 106 (see also Second Dacian War).Sometime around 272, at the Moesian city of Naissus or Nissa (modern Niš in Serbia), future emperor Constantine I was born.