However, in 1462, John of Islay had over-reached himself by entering into a treacherous agreement with Edward IV of England and Mackenzie later played a significant part in the negotiations between John of Islay and James III that led to the former's surrender of the Earldom of Ross in 1476. Mackenzie was rewarded in 1477 with a charter from the Crown to some of the lands renounced by the Earl of Ross, namely Strathconan, Strathbraan, and Strathgarve, and was confirmed in his lands in Kintail. It was probably at this point that Mackenzie moved his family's chief residence from Eilean Donan in Kintail to Kinellan Castle, near Strathpeffer. After this the Barons of Kintail held all their lands quite independently of any superior but the Crown.