Roger Mortimer, 1st Earl of March on 22 May 1306, in a lavish ceremony in Westminster Abbey with two hundred and fifty-nine others, he was knighted by Edward and granted livery of his full inheritance. His adult life began in earnest in 1308, when he went to Ireland in person to enforce his authority. This brought him into conflict with the de Lacys, who turned for support to Edward Bruce, brother of Robert Bruce, King of Scots. Mortimer was appointed Lord Lieutenant of Ireland by Edward II on 23 November 1316. Shortly afterwards, at the head of a large army, he drove Bruce to Carrickfergus and
Christopher Seton letter of excommunication was issued naming the Earl of Carrick and three other knights, Sir Alexander Lindsay, Sir Christopher and his brother John Seton as John Comyn's murderers. Seton was also present at the coronation of his brother in-law King Robert I, King of Scots, at Scone on 25–26 March 1306. Some accounts have him present at the Battle of Methven on 19 June 1306 but Duncan places him at Loch Doon Castle, an important castle for the Earls of Carrick and one of three that Robert tried to hang on to, but Loch Doon fell about 14 August. Loch