Clan Sweeney supporters of the powerful MacDougall Lords of Lorne who supported John Balliol as patriots, as long as John was king of Scotland. After the murder of John Comyn, the nephew of Balliol, by Bruce in 1306, the First War of Scottish Independence became at one and the same time a civil war. The Balliol and Comyn parties taking the side of the English in opposition to Bruce, crowned Robert I of Scotland on 25 March 1306. This was an era of constantly shifting alliances, and in 1301 John MacSween was in alliance with Aonghus Óg Mac Domhnaill, Lord of Islay
John de Warenne, 7th Earl of Surrey Scottish throne, accompanied him on his campaign in Lothian. Balliol created Warenne earl of Strathern, but this was in name only for the properties of the earldom were held by the Scots. Warenne died in 1347 and is buried at the monastery of Lewes. He was succeeded as earl by his nephew Richard Fitzalan, who was also earl of Arundel. On 25 May 1306 Warenne married Joan of Bar, daughter of count Henry III of Bar and Eleanor of England, eldest daughter of king Edward I of England. The two were soon estranged and lived apart, and had no children,