Roman Frontier or Fortified Road? GIS Analysis of the Gask Ridge
Channel: Recording Archaeology
Date: 2018-12-19

Shortly after arriving in Scotland in the early AD 70s, the Roman Army constructed a series of forts, fortlets, and towers in the central belt between the Forth-Clyde valley and the river Tay. This assembly of Roman military infrastructure is known as the Gask Frontier or Gask System, as the main line of towers stand along the Gask Ridge. These forts and towers predate all other frontier systems in the Roman Empire, and are therefore regarded as a prototype frontier. The Gask system consists of three sections: the Gask Ridge line, which is located along a Roman road; the Highland line, with forts located at the entrances to the Highland glens; and the Strathmore line, which is likely a northern continuation of the Gask Ridge line. It is thought that the towers would have been used to monitor the surrounding landscape, and pass important messages or warnings to the forts, leading to the mobilisation of soldiers if needed. This monitoring and communication system is why these lines of forts and towers have been called a frontier, as it would allow the Roman Army to protect the Roman-controlled territory that lies to the south-east of the Gask Ridge, and keep the locals under control. For this frontier system to function properly, excellent visibility from the towers, and good intervisibility between the towers and forts is required. This paper will use regular, cumulative, fuzzy and probable viewshed analysis methods to analyse the visibility from and between the infrastructure that makes up the Gask Ridge system and determine if it has the visibility required to function as a frontier, or if it was designed to serve another purpose, such as a fortified road system.

Kathryn Murphy