Glensassunn, a little glen in the E of Fortingall parish, Perthshire, 3 miles S by W of Kinloch Rannoch. Its name, signifying the ' Englishman's glen, ' arose from the fact that during the War of Independence, a body of English passed this way to meet an opposing force of Robert Bruce at Innerhadden.—Ord. Sur., sh 55, 1869.

(F.H. Groome, Ordnance Gazetteer of Scotland (1882-4); © 2004 Gazetteer for Scotland)