The chronology of subsequent events is uncertain, but it is generally believed that early in 115 Trajan launched a Mesopotamian campaign, marching down towards the Taurus mountains in order to consolidate territory between the Tigris and Euphrates rivers. He placed permanent garrisons along the way to secure the territory.[43] While Trajan moved from west to east, Lusius Quietus moved with his army from the Caspian Sea towards the west, both armies performing a successful pincer movement,[44] whose apparent result was to establish a Roman presence into the Parthian Empire proper, with Trajan taking the northern Mesopotamian cities of Nisibis and Batnae and organizing a province of Mesopotamia, including the Kingdom of Osrhoene – where King Abgaros VII submitted to Trajan publicly[45] – as a Roman protectorate.[46] This process seems to have been completed at the beginning of 116, when coins were issued announcing that Armenia and Mesopotamia had been put under the authority of the Roman people.[47] The area between the Khabur River and the mountains around Singara seems to have been considered as the new frontier, and as such received a road surrounded by fortresses.[48]