Julianus, who had already distinguished himself in Moesia under Otho and Vespasian.  Following Decebalus into his own dominions, he was not content to remain in the plains, but pursued him into his mountain retreats, where he completely overthrew him in a pitched battle and compelled him to sue for peace.  It is in the accounts of this expedition that mention is first made of regular roads in Dacia, and two passes, the Vulcan and Rothenthurm (or Red Tower), are referred to.  A place called Tapae is also named, near to which Julianus is said to have overthrown Decebalus, and where subsequently Trajan obtained a victory over the same prince; but so much doubt attaches to the movements of Julianus that it will be better for the present to defer any reference to those localities.  The whole account of Julianus’s campaign in Dacia is mixed up with legendary tradition.  It is said that he threatened the capital of Dacia, Sarmizegethusa, and that he would have succeeded in capturing it and in reducing the whole country but for a stratagem of Decebalus, who caused trees to be cut down to a man’s height in the woods through which the Romans had to pass, and clothed them in armour, which so terrified the soldiers as to stay their progress.  According to another account he cut the trees through their trunks but allowed them to stand, and when the Romans attempted to force their way through with their engines of war, the trees fell on them and killed them.  Whether it was the difficulty encountered by the Roman general in attempting to cope with his warlike enemy in his mountains and forests, where the arts of war as practised by the former were not so readily applicable as in the plains, or the more probable circumstance that Domitian had been unsuccessful in an expedition against two other tribes, the Quadi and Marcomanni, and needed the support of Julianus, certain it is that the overtures of Decebalus were at length received favourably, and a peace was concluded with him in the year 90, which was less favourable to the victors than to the conquered.  Decebalus refused to treat in person with the Roman general, but sent one of his chiefs (some historians say his brother), with whom the conditions were arranged.  According to Roman accounts Decebalus restored the Roman prisoners, acknowledged the supremacy of Domitian, and accepted sovereignty at his hands.  It subsequently transpired, however, that this was not the whole treaty, and that Domitian agreed to pay the Dacian king an annual tribute, and to send him a number of skilled artificers to teach him the art of constructing works and fabricating arms upon the Roman model.  Domitian then celebrated a triumph, which was however made a subject of ridicule by those who were aware of the actual result of the expedition.

We now approach a crisis in the history of Dacia.  During the short reign of Nerva nothing was undertaken against the country, and Decebalus continued to harass and annoy the Romans in Moesia until Trajan (who had been adopted by Nerva) ascended the throne (A.D. 98).