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 to his eldest son, Robert, the future king, so as to protect the Bruce's kingship claim while their middle lord (Robert the Bruce's father) now held only English lands. While the Bruces' bid for the throne had ended in failure, the Balliols' triumph propelled the eighteen-year-old Robert the Bruce onto the political stage in his own right. Even after John's accession, Edward still continued to assert his authority over Scotland and relations between the two kings soon began to deteriorate. The Bruces sided with King Edward against King John and his Comyn allies. Robert the Bruce and his father both