. ▁ ▁Mac cus ▁appears ▁to ▁have ▁been ▁an ▁elder ▁brother ▁of ▁G of raid ▁mac ▁Ara ilt . ▁A ▁sister ▁of ▁Mac cus ▁and ▁G of raid , ▁or ▁perhaps ▁a ▁daughter ▁of ▁the ▁latter , ▁may ▁have ▁been ▁M á el ▁Mu ire , ▁wife ▁of ▁G illa ▁P át ra ic ▁mac ▁D onn ch ada , ▁King ▁of ▁Os ra ige . ▁Specific ▁evidence ▁of ▁a ▁famil ial ▁relationship ▁between ▁M á el ▁Mu ire ▁and ▁the ▁Me ic ▁Ara ilt ▁may ▁be ▁preserved ▁by ▁the ▁tw elf th - century ▁B ans hen chas , ▁a ▁source ▁that ▁ident ifies ▁the ▁mother ▁of ▁G illa ▁P át ra ic ' s ▁son , ▁D onn ch ad , ▁as ▁M á el ▁Mu ire , ▁daughter ▁of ▁a ▁certain ▁Ar alt ▁mac ▁G of raid . ▁One ▁possibility ▁is ▁that ▁this ▁source ▁has ▁err one ously ▁revers ed ▁the ▁patron ym ▁of ▁Mac cus ' ▁brother . ▁Another ▁brother ▁of ▁Mac cus ▁may ▁have ▁been ▁E ir í kr ▁Har ald sson , ▁a ▁Vik ing ▁who ▁ruled ▁the ▁Kingdom ▁of ▁North umb ria ▁in ▁the ▁mid ▁part ▁of ▁the ▁t enth ▁century . ▁Although ▁non - cont empor ary ▁Sc and in av ian ▁sources ▁identify ▁this ▁figure ▁with ▁the ▁like - named ▁Norwegian ▁royal ▁E ir í kr ▁bl ó ð ø x , ▁there ▁is ▁reason ▁to ▁suspect ▁that ▁these ▁sources ▁have ▁err one ously ▁confl ated ▁two ▁different ▁individuals , ▁and ▁that ▁the ▁former