As a result, in the expansion that followed the outbreak of the War of the Austrian Succession, in 1743 Lascelles was made as Colonel of the 47th Foot; raised in 1741, it was employed on the construction of a military road near Loch Lomond, part of a new route from Dumbarton to Inverary. The road was completed in May 1745, two months before Charles Stuart launched the 1745 Rising. After detaching two companies to garrison Edinburgh Castle, Lascelles and the rest of his regiment joined the field army commanded by Sir John Cope.