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
Battle of Halidon Hill ultimate victor. The Treaty of Northampton in 1328 brought an end to over thirty years of intermittent warfare following the defeat of Edward II by Robert Bruce. Bruce's own death the following year opened up an opportunity for the disinherited, Balliol and the English to invade Scotland once more. In 1332 under the leadership of Edward Balliol, son of King John Balliol, and Henry Beaumont, 4th Earl of Buchan, these men invaded Scotland with the full support of Edward III, defeating the Bruce loyalists at the Battle of Dupplin Moor. Building on this success Balliol was crowned King of Scotland.