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 from English rule (having received a reply to offers of assistance from Donal O'Neil, king of Tyrone), and to open a second front in the continuing wars with England. Bruce was even crowned as High King of Ireland in 1316. Robert later went there with another army to assist his brother. In conjunction with the invasion, Bruce popularised an ideological vision of a "Pan-Gaelic Greater Scotia" with his lineage ruling over both Ireland and Scotland. This propaganda campaign was aided by two factors. The first was his marriage alliance from 1302 with the de Burgh family of the Earldom of