▁defeated ▁at ▁the ▁Battle ▁of ▁B ouv ines ▁in ▁one ▁of ▁the ▁most ▁decis ive ▁and ▁symbol ic ▁batt les ▁in ▁French ▁history . ▁The ▁battle ▁had ▁both ▁important ▁and ▁high - profile ▁consequences . ▁John ' s ▁nep hew ▁Otto ▁retre ated ▁and ▁was ▁soon ▁over th rown ▁while ▁King ▁John ▁agreed ▁to ▁a ▁five - year ▁tr uce . ▁Philip ' s ▁decis ive ▁victory ▁was ▁cru cial ▁in ▁ordering ▁politics ▁in ▁both ▁England ▁and ▁France . ▁The ▁battle ▁was ▁instrument al ▁in ▁forming ▁the ▁absolute ▁mon archy ▁in ▁France . ▁ ▁John ' s ▁defe ats ▁in ▁France ▁weak ened ▁his ▁position ▁in ▁England . ▁The ▁re bell ion ▁of ▁his ▁English ▁v ass als ▁resulted ▁in ▁the ▁treat y ▁called ▁Mag na ▁Cart a , ▁which ▁limited ▁royal ▁power ▁and ▁established ▁common ▁law . ▁This ▁would ▁form ▁the ▁basis ▁of ▁every ▁constitution al ▁battle ▁through ▁the ▁th ir teenth ▁and ▁four teenth ▁centuries . ▁However , ▁both ▁the ▁bar ons ▁and ▁the ▁crown ▁failed ▁to ▁ab ide ▁by ▁the ▁terms ▁of ▁Mag na ▁Cart a , ▁leading ▁to ▁the ▁First ▁Bar ons ' ▁War ▁in ▁which ▁the ▁re bel ▁bar ons ▁invited ▁an ▁invasion ▁by ▁Prince ▁Louis . ▁This ▁is ▁considered ▁by ▁some ▁histor ians ▁to ▁mark ▁the ▁end ▁of ▁the ▁An ge vin ▁period ▁and ▁the ▁beginning ▁of ▁the ▁Plant agen et ▁dynast y ▁with ▁John ' s ▁death ▁and ▁William ▁Marshall ' s ▁appointment ▁as ▁the ▁prote ctor ▁of ▁the ▁nine - year - old ▁Henry ▁III