▁Mac D onn ell ▁or ▁if ▁any ▁possible ▁al liance ▁may ▁have ▁been ▁influ ential . ▁ ▁In ▁the ▁opinion ▁of ▁W . ▁F . ▁T . ▁Butler ▁the ▁Mac D onn ell ▁claim ▁was ▁of ▁doubt ful ▁leg ality , ▁while ▁according ▁to ▁George ▁Hill ▁they ▁did ▁not ▁establish ▁a ▁permanent ▁( or ▁any ) ▁presence ▁in ▁the ▁Gl ens ▁until ▁Alexander ▁Car rag h ▁in ▁the ▁early ▁ 1 6 th ▁century , ▁who ▁is ▁noticed ▁campaign ing ▁in ▁the ▁Irish ▁ann als ▁in ▁the ▁ 1 5 2 0 s . ▁He ▁was ▁a ▁strong ▁leader ▁with ▁a ▁large ▁following , ▁and ▁it ▁is ▁in ▁this ▁de cade ▁the ▁B isset ts ▁appear ▁to ▁lose ▁control ▁of ▁their ▁lord ship ▁following ▁the ▁Battle ▁of ▁Kno ck av oe . ▁One ▁of ▁Alexander ▁Car rag h ' s ▁sons , ▁the ▁celebrated ▁Sor ley ▁Boy , ▁was ▁finally ▁allowed ▁by ▁Elizabeth ▁I ▁in ▁ 1 5 6 0 ▁to ▁be ▁a ▁ten ant ▁of ▁the ▁lands ▁he ▁claimed ▁" by ▁inheritance ," ▁but ▁the ▁Mac D onn ells ▁continued ▁to ▁struggle ▁to ▁gain ▁a ▁fo oth old ▁because ▁of ▁Ul ster ' s ▁leading ▁prince , ▁Sh ane ▁O ' Ne ill , ▁who ▁contin ually ▁har ass ed ▁them . ▁In ▁ 1 5 7 3 , ▁six ▁years ▁after ▁O ' Ne ill ' s ▁death , ▁Sor ley ▁Boy ▁( re -) pet ition ed , ▁and ▁this ▁time ▁for ▁" a ▁portion ▁of ▁the ▁G lyn ns