Roman roads in Britannia the military road from Carlisle to Corbridge, was built under the Emperor Trajan (ruled 98–117 AD) along the line of the future Hadrian's Wall, which was constructed by his successor Hadrian in 122–132 AD. Scotland ("Caledonia"), including England north of Hadrian's Wall, remained mostly outside the boundaries of "Britannia" province, as the Romans never succeeded in subjugating the entire island, despite a serious effort to do so by governor Gnaeus Julius Agricola in 82–84 AD. However, the Romans maintained a system of forts in the lowland region ca. 80–220 AD to control the indigenous population beyond Hadrian's Wall and annexed
Scotland during the Roman Empire as unified ideas until centuries later. In fact, the Roman Empire influenced every part of Scotland during the period: by the time of the Roman withdrawal from Britain around 410, the various Iron Age tribes native to the area had united as, or fallen under the control of, the Picts, while the southern half of the country was overrun by tribes of Romanized Britons. The Scoti (Gaelic Irish raiders) who would give Scotland its English name, had begun to settle along the west coast. All three groups may have been involved in the Great Conspiracy that overran Roman Britain in