Battle of Alnwick ( 1174 ) The Battle of Alnwick ( 1174 ) is one of two battles fought near the town of Alnwick , in Northumberland , England . In the battle , which occurred on 13 July 1174 , William I of Scotland , also known as William the Lion , was captured by a small English force led by Ranulf de Glanvill . Background . William had inherited the title of Earl of Northumbria in 1152 . However , he had to give up this title to King Henry II of England in 1157 . He spent much of his reign trying to regain his lost territory . In 1173 , whilst Henry II was occupied in fighting against his sons in the Revolt of 1173 – 1174 , William saw his opportunity and invaded Northumbria . He advanced on Newcastle but found the partly built stone castle too strong to allow him to take the town . He also attacked Prudhoe Castle but found the defences too strong . Unwilling to undertake a lengthy siege , William returned to Scotland . In 1174 , William again invaded Northumbria with an even larger army that included a contingent of Flemish mercenaries . The army was said to have numbered eighty thousand men , but this is almost certainly an exaggeration . This time he avoided Newcastle but attacked Prudhoe Castle again . The castle had been strengthened since the previous year and after a siege of three days William moved north to besiege Alnwick . William divided his army into three columns and one of these , under the command of Duncan , Earl of Fife , attacked Warkworth and set fire to the church of St Lawrence with a large number of refugees inside . The battle . William made the fatal error of allowing his army to spread out , instead of concentrating them around his base at Alnwick . On the night of 11 July , a party of about four hundred mounted knights , led by Ranulf de Glanvill , set out from Newcastle and headed towards Alnwick . This small fighting force contained several seasoned knights , who had fought against the Scots before . They reached Alnwick shortly after dawn after becoming lost in heavy fog . There they found William ’ s encampment , where the Scottish king was only protected by a bodyguard of perhaps sixty fighting men . At the sound of alarm , William rushed from his tent and hurriedly prepared to fight . The English force charged and the Scottish king and his bodyguard met the charge head on . The fighting did not last long . William ’ s horse was killed beneath him and he was captured . Those of his followers who had not been killed surrendered . Aftermath . William was brought back to Newcastle as a captive . His army found itself leaderless and wandered back to Scotland . William was held at Newcastle for a time but it was not considered strong enough , and he was finally moved to Falaise in Normandy . Whilst he was there , Henry sent an army to occupy part of Scotland , with its five strongest castles : Roxburgh , Berwick , Jedburgh , Edinburgh and Stirling . To obtain his freedom , William was forced to sign the Treaty of Falaise , under which he swore an oath of allegiance to the English king and agreed to the garrisoning of the captured castles by English soldiers at Scottish expense . When William was released , after signing the treaty , he travelled back to Scotland via Newcastle , and was attacked by a mob ; such was the antipathy of the local people towards Scottish invaders . Subsequent history . The Treaty of Falaise lasted for fifteen years until Richard the Lionheart effectively sold the castle back to William in order to fund his crusade to the Holy Land . This was the last attempt by a Scottish king to regain lost territories in northern England . In 1237 , under the Treaty of York , Alexander II of Scotland abandoned his forefathers ’ claims to Northumbria and Cumbria , and set the boundary between the two kingdoms as running between the Solway Firth ( in the west ) , and the mouth of the River Tweed ( in the east ) , as it still does today .