 During the 1715 rising, he and the Lord Lieutenant of Cumberland, the Earl of Carlisle assembled the Cumberland and Westmorland militia at Penrith's Beacon Fell with the posse comitatus, but the citizen army disintegrated upon the approach of the Earl of Derwentwater's troops.Lonsdale found twenty of his servants the only persons faithful to him, and was compelled to retire to Appleby Castle.His brave, if futile conduct, won admiration.