Clan Sinclair to St Briavels Castle, and in 1296 he swore fealty to Edward I of England. In 1303 the Battle of Roslin took place where Scots under Henry Sinclair of Rosslyn and the Clan Comyn defeated an English force. The Battle of Loudoun Hill took place in 1307 where Scots under Robert the Bruce, assisted by Henry Sinclair of Rosslyn again defeated the English. The family initially favoured John Balliol's claim to the throne but later it became paramount that they gave their loyalty to Robert the Bruce. The Battle of Bannockburn was fought in 1314, where the Clan Sinclair fought
Robert the Bruce at Ramsey in the Isle of Man, laid siege to Castle Rushen in Castletown, capturing it on 21 June 1313 and denying the English the island's strategic importance. The eight years of exhausting but deliberate refusal to meet the English on even ground have caused many to consider Bruce one of the great guerrilla leaders of any age. This represented a transformation for one raised as a feudal knight. By 1314, Bruce had recaptured most of the castles in Scotland held by the English and was sending raiding parties into northern England as far as Carlisle. In response, Edward II