It was important in controlling the Highland Scottish clans , particularly in the Jacobite uprisings of the 18th century . This is recognized by the towns of Fort William ( population ~ 10,000 ) in the south , Fort Augustus ( popln . Its strategic importance in controlling the Highland Scottish clans , particularly around the time of the Jacobite uprisings of the 18th century , is recognized by the presence of the towns of Fort William in the south , Fort Augustus in the middle of the Glen , and Fort George , just to the north of Inverness .