Battle of Lincoln ( 1217 ) The Second Battle of Lincoln occurred at Lincoln Castle on 20 May 1217 , during the First Barons ' War , between the forces of the future Louis VIII of France and those of King Henry III of England . Louis ' forces were attacked by a relief force under the command of William Marshal , 1st Earl of Pembroke . The Comte du Perche , commanding the French troops , was killed and this heavy defeat led to Louis being expelled from his base in the southeast of England . This event is known as “ Lincoln Fair ” after the looting that took place afterwards . The citizens were loyal to Louis so Henry ’ s forces sacked the city . Background . In 1216 the First Barons ' War of the English succession took a new turn when Prince Louis of France entered London and was proclaimed King of England . He was supported by various English barons who resisted the rule of King John . When John died in the middle of the war , his 9 year - old son Henry III was crowned . Once John died , many barons were willing to change sides and fight for Henry against Prince Louis ' claim . The regent of Henry , a famous knight and excellent tournament fighter named William Marshal , had the power of the king ' s command . Marshal ordered all nobles with a Castle in England to a muster in Newark . Approximately 400 Knights , 250 crossbowmen , and a larger auxiliary force of both mounted and foot soldiers were assembled . From there they would march to break a long siege by an army of Prince Louis at the city of Lincoln . Battlefield . Medieval Lincoln was an ancient walled city with a Norman Castle near its centre , straddling a crossroads of two important Roman - built highways : Ermine Street and Fosse Way . These trans - England routes were longtime staples of national trade and government . It was thus a strategic location . There , 150 years earlier , William the Conqueror ordered the construction of Lincoln Castle , built on a hilltop over an old Roman fort . At the time of the battle in May 1217 , the city of Lincoln had been taken by Louis ' forces . However , the castle remained intact . Its garrison — loyal to King Henry — continued to defend the important fortification from forces loyal to Prince Louis , led by the Count of Perche . Battle . From the town of Stowe a few miles to the northwest of Lincoln , Marshal ' s forces made their approach . Though the advance was known to the Perche , his knights debated about intelligence on the strength of the enemy . Those who believed Marshal ' s force was relatively small in number favoured an offensive plan : a meeting in an open battlefield at the base of the hill , before Marshal could reach the city gates . Those who believed Marshal had a dangerously large force favoured a more defensive plan : delay Marshal at the gates of the city wall , and at the same time press the siege , capture the castle , and occupy this much stronger position . The defensive plan was taken , though not without some continuing dissension . Marshal proceeded to the section of the city walls nearest the castle , at the north gate . The entire force of Marshal ' s crossbowmen led by the nobleman Falkes de Breauté assaulted and won the gate . Perche ' s forces did not respond , but continued the castle siege . The north gate was secured by Marshal ' s main force , while Breauté ' s crossbowmen took up high positions on the rooftops of houses . Volleys of bolts from this high ground caused rapid death , damage and confusion among Perche ' s forces . Then , in the final blow , Marshal committed his knights and footsoldiers in a charge against Perche ' s siege . Perche was offered a surrender , but instead fought to the death as the siege collapsed into a scattered rout . Those of Louis ' army who were not captured fled Lincoln out the south city gate , to London . The whole of the battle had taken about six hours . Aftermath and effects . The city of Lincoln — on the pretense of being in league with Louis — was pillaged by the victorious army , in an event called the Lincoln Fair . To the south , inhabitants of towns between Lincoln and London ambushed and killed some French soldiers in the flight south to London . The Battle of Lincoln was the turning point in the First Barons ' War . Many of Henry ' s enemies — barons who had supported Louis , and who helped supply , organise and command his military forces — were captured at Lincoln . Reinforcements for Louis were then sent across the English Channel under the command of Eustace the Monk . However the French ships were defeated by Hubert de Burgh in the Battle of Dover . This defeat of the French fleet greatly reduced the French threat to the English crown and so Prince Louis and his remaining forces had to return to France . In September 1217 , the treaty of Lambeth forced Louis not only to give up his claim to the English throne but to eject Eustace ' s brothers from the Channel Islands .