▁and ▁Carl ▁who ▁made ▁their ▁debut ▁appearances ▁in ▁February . ▁ ▁Development ▁ ▁Character isation ▁During ▁his ▁time ▁on ▁the ▁show ▁Matthew ▁was ▁character ised ▁as ▁being ▁the ▁most ▁head strong ▁and ▁manip ulative ▁of ▁the ▁four ▁King ▁brothers . ▁He ▁was ▁proven ▁capable ▁of ▁causing ▁cha os ▁wherever ▁he ▁went , ▁ru ining ▁relationships ▁and ▁even ▁causing ▁death . ▁However ▁he ▁was ▁also ▁shown ▁to ▁be ▁one ▁to ▁stick ▁his ▁neck ▁out ▁for ▁his ▁family ▁and ▁was ▁even ▁hint ed ▁to ▁have ▁had ▁police ▁officer ▁D CI ▁Grace ▁Bar ra cl ough ▁( G ly nis ▁Bar ber ) ▁run ▁over ▁and ▁killed ▁in ▁order ▁to ▁prevent ▁his ▁brother ▁Carl ▁( Tom ▁L ister ) ▁being ▁taken ▁down ▁for ▁the ▁murder ▁of ▁their ▁father . ▁However ▁Matthew ▁was ▁also ▁character ised ▁as ▁a ▁not orious ▁woman iser , ▁enjo ying ▁fl ings ▁with ▁the ▁lik es ▁of ▁Louise ▁App leton ▁( Em ily ▁Sym ons ). ▁However ▁he ▁is ▁arg u ably ▁best ▁remembered ▁for ▁his ▁affair ▁with ▁his ▁brother ▁Jimmy ' s ▁( N ick ▁Mil es ) ▁wife ▁Sad ie ▁( P ats y ▁K ens it ), ▁which ▁helped ▁to ▁show ▁that ▁the ▁character ▁would ▁go ▁to ▁any ▁lengths ▁to ▁get ▁his ▁own ▁way . ▁However ▁another ▁more ▁vulner able ▁side ▁of ▁Matthew ▁was ▁shown ▁through ▁his ▁rom antic ▁l ia ison ▁with ▁P erd ita ▁Hy de - S inc la ir ▁( Ge org ia ▁S low e ), ▁the ▁wife ▁of ▁Matthew ' s ▁step bro