After the 1266 Treaty of Perth, Garmoran became a Scottish crown dependency – the "Lordship of Garmoran" – still ruled by the MacRory, until the final MacRory heir was Amy of Garmoran. Most of the remainder of the Kingdom had become the "Lordship of the Isles", ruled by the MacDonalds, whose leader, John of Islay, married Amy. After the birth of three sons, he divorced Amy and married the king's niece, in return for a substantial dowry. As part of the arrangement, John deprived his eldest son, Ranald, of the ability to inherit the Lordship of the Isles, in favour of a son by his new wife; as compensation, he made Ranald the Lord of Garmoran.