Robert "Riabhach" ("Grizzled") Duncanson, 4th Chief of Clann Dhònnchaidh, was a strong supporter of King James I (1406–1437) and was incensed by his murder at the Blackfriars Dominican Friary in Perth. He tracked down and captured two of the regicides, Sir Robert Graham and the King's uncle Walter Stewart, Earl of Atholl, as they hid above Invervack in Atholl, and turned them over to the Crown. They were tortured to death in the Grassmarket in Edinburgh on the orders of the Regent, James I's widow, Joan Beaufort (d. 1445). The Collins "Scottish Clan & Family Encyclopedia" states that they were put to death with considerable savagery. The Robertson crest badge of a right hand upholding an imperial crown was awarded by James II (1437–60) to the 4th chief on 15 August 1451 as a reward for capturing his father's assassins. The highly unusual third supporter (below the shield) on the Robertson coat of arms, of a "savage man in chains" is in reference to the capture of Graham. It is in honour of Robert "Riabhach" that his descendants took the name Robertson. James II also erected the clan lands into the Barony of Struan, which formerly took in extensive lands in Highland Perthshire, notably in Glen Errochty, the north and south banks of Loch Tay and the area surrounding Loch Rannoch. None of these lands are any longer in the possession of the clan.