During Robert's chieftaincy of his clan, a feud arose between the Earl of Sutherland (chief of Clan Sutherland) and the Earl of Caithness (chief of Clan Sinclair), caused by the latter hunting on the former's lands. Robert, being connected to the Sutherlands by marriage, sent a number of men from his clan to support the Earl of Sutherland. The Clan Mackay and the MacLeods of Assynt also assisted the Sutherlands. The Earl of Caithness gathered his forces and proceeded into Sutherland, however having heard of the large army that faced him he sent messengers to Sutherland with proposals of a peaceful settlement. His proposals of peace were refused and he was assured of battle the next morning. The Earl of Sutherland's army lined up, consisting of the Mackays on the left wing, the Sutherlands in the centre and the Munros and MacLeods on the right wing. As they advanced, Caithness's men fled, and the Munros went home not having engaged in battle, it is said to their disappointment.