Robert II's third son was Robert Stewart, 1st Duke of Albany, who was Regent of Scotland during part of the reigns of his father, brother, and nephew James I of Scotland. Robert II's fourth son was Alexander Stewart, Earl of Buchan, who was famed as the "Wolf of Badenoch" and was responsible for the destruction of Elgin Cathedral. When James I of Scotland came of age, he curbed the power of his cousins, the Albany Stewarts. He beheaded Murdoch Stewart, 2nd Duke of Albany, eldest son of the former regent Robert Stewart. Two of Murdoch's sons, Walter and Alexander (Alasdair), were both executed as well. As the Chief of the Stewarts was also the occupant of the throne, the relationship between the various branches or members of the family differed from the usual ties between clansmen and their Chief. The family did however have their own badge and tartan to distinguish them. Apart from the royal house of Stewart, the three main branches of the clan that settled in the Scottish Highlands during the 14th and 15th centuries were the Stewarts of Appin, Stewarts of Atholl and Stewarts of Balquhidder. Today the Earls of Galloway are considered the senior line of the Clan Stewart. The Stewarts of Appin descend from Sir John Stewart of Bonkyll, son of Alexander Stewart, 4th High Steward of Scotland. Sir John's younger son, James Stewart, was killed in 1333 at the Battle of Halidon Hill. His grandson married the heiress of the Lord of Lorne (chief of Clan MacDougall). He was the first Stewart Lord of Lorne. The Stewarts of Appin supported the royalist cause during the Civil War of the 17th century and also supported the deposed Stuart monarchs during the Jacobite rising of 1715 and Jacobite rising of 1745. The Stewarts of Atholl are descended from a son of Alexander Stewart, Earl of Buchan, the "Wolf of Badenoch". James Stewart built a strong castle at Garth where he settled at the end of the 14th century. Queen Joanna, widow of James I of Scotland married the "Black Knight of Lorne" who was descended from the fourth High Steward. Their son was John Stewart of Balveny who was granted the Earldom of Atholl by his half-brother, James II of Scotland. He supported his brother, commanding the royal forces that opposed the rebellion by the Lord of the Isles.