▁her ▁uncle , ▁Edward ▁IV , ▁at ▁the ▁Battle ▁of ▁Bar net . ▁Her ▁father , ▁already ▁Duke ▁of ▁Clar ence , ▁was ▁then ▁created ▁Earl ▁of ▁Sal is bury ▁and ▁of ▁War wick . ▁Edward ▁IV ▁declared ▁that ▁Margaret ' s ▁younger ▁brother ▁Edward ▁should ▁be ▁known ▁as ▁Earl ▁of ▁War wick ▁as ▁a ▁cour tes y ▁title , ▁but ▁no ▁peer age ▁was ▁ever ▁created ▁for ▁him . ▁Margaret ▁would ▁have ▁had ▁a ▁claim ▁to ▁the ▁Ear ld om ▁of ▁War wick , ▁but ▁the ▁ear ld om ▁was ▁for fe ited ▁on ▁the ▁att ain der ▁of ▁her ▁brother ▁Edward . ▁ ▁Margaret ' s ▁mother ▁died ▁when ▁she ▁was ▁three , ▁and ▁her ▁father ▁had ▁two ▁servants ▁killed ▁whom ▁he ▁thought ▁had ▁poison ed ▁her . ▁George ▁pl otted ▁against ▁Edward ▁IV , ▁and ▁was ▁att aint ed ▁and ▁executed ▁for ▁tre ason ; ▁his ▁lands ▁and ▁titles ▁were ▁for fe ited . ▁Edward ▁IV ▁died ▁when ▁Margaret ▁was ▁ten , ▁and ▁her ▁uncle ▁Richard , ▁Duke ▁of ▁Gl ouc ester , ▁declared ▁that ▁Edward ' s ▁marriage ▁was ▁invalid , ▁his ▁children ▁il leg it imate , ▁and ▁that ▁Margaret ▁and ▁her ▁brother ▁Edward ▁were ▁de bar red ▁from ▁the ▁throne ▁by ▁their ▁father ' s ▁att ain der . ▁Mar ried ▁to ▁Anne ▁Ne ville , ▁younger ▁sister ▁to ▁Margaret ' s ▁mother ▁Isabel , ▁Richard ▁assumed ▁the ▁throne ▁himself ▁as ▁Richard ▁III . ▁ ▁Richard ▁III ▁sent ▁the ▁children ▁to ▁Sher iff ▁H utton ▁Castle ▁in