negotiated by Domitian's ministers with the powerful Dacian king Decebalus. Dacia would be reduced by Trajan's Rome to a client kingdom in the first war (101102), followed by a second war that ended in actual incorporation into the Empire of the trans-Danube border group of Dacia. According to the provisions of Decebalus's earlier treaty with Rome, made in the time of Domitian, Decebalus was acknowledged as rex amicus, that is, client king; in exchange for accepting client status, he received from Rome both a generous stipend and a steady supply of technical experts. The treaty seems to have allowed Roman troops the right of passage through the Dacian kingdom in order to attack the Marcomanni, Quadi and Sarmatians. However, senatorial opinion never forgave Domitian for paying what was seen as tribute to a barbarian king. Unlike the Germanic tribes, the Dacian kingdom was an organized state capable of developing alliances of its own, thus making it a strategic threat and giving Trajan a strong motive to attack it. In May of 101, Trajan launched his first campaign into the Dacian kingdom, crossing to the northern bank of the Danube and defeating the Dacian army at Tapae (see Second Battle of Tapae), near the Iron Gates of Transylvania. It was not a decisive victory, however. Trajan's troops took heavy losses in the encounter, and he put off further campaigning for the year in order to regroup and reinforce his army. Nevertheless, the battle was considered a Roman victory and Trajan strived to ultimately consolidate his position, including other major engagements, as well as the capture of Decebalus' sister as depicted on Trajan's Column. The following winter, Decebalus took the initiative by launching a counter-attack across the Danube further downstream, supported by Sarmatian cavalry, forcing Trajan to come to the aid of the troops in his rearguard. The Dacians and their allies were repulsed after two battles in Moesia, at Nicopolis ad Istrum and Adamclisi. Trajan's army then advanced further into Dacian territory, and, a year later, forced Decebalus to submit. He had to renounce claim to some regions of his kingdom, return runaways from Rome then under his protection (most of them technical experts), and surrender all his war machines. Trajan returned to Rome in triumph and was granted the title Dacicus. The peace of 102 had returned Decebalus to the condition of more or less harmless client king; however, he