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 the heavy fighting. The historian Roy Haines describes the defeat as a "calamity of stunning proportions" for the English, whose losses were huge. In the aftermath of the defeat, Edward retreated to Dunbar, then travelled by ship to Berwick, and then back to York; in his absence, Stirling Castle quickly fell. Freed from English threats, Scotland's armies could now invade northern England. Bruce also drove back a subsequent English expedition north of the border and launched raids into Yorkshire and Lancashire. Buoyed by his military successes, Bruce's forces also invaded Ireland in 1315, in an attempt to free the country