▁cr us ade , ▁died ▁def ending ▁it ▁from ▁the ▁Muslim s ▁and ▁Arn au ▁took ▁over ▁the ▁reg ency ▁of ▁Ur g ell ▁for ▁the ▁young ▁Er m eng ol ▁IV . ▁ ▁In ▁ 1 0 7 2 ▁Arn au ▁went ▁on ▁a ▁pil gr image ▁to ▁Santiago ▁de ▁Com post ela . ▁Upon ▁his ▁return ▁he ▁dict ated ▁his ▁test ament , ▁which ▁is ▁preserved . ▁It ▁contains ▁the ▁second ▁mention ▁of ▁a ▁set ▁of ▁nin ety - six ▁rock ▁cry stal ▁ch ess ▁pieces ▁called ▁the ▁" U rg ell ▁( or ▁À ger ) ▁ch ess men ". ▁Their ▁earliest ▁mention ▁is ▁in ▁the ▁ 1 0 6 8 ▁will ▁of ▁Arn au ' s ▁wife ▁Ar send a . ▁They ▁are ▁craft ed ▁in ▁an ▁abstract ▁Islam ic ▁design , ▁imp lying ▁that ▁they ▁were ▁originally ▁from ▁south ▁of ▁the ▁front ier . ▁On ▁his ▁death bed ▁he ▁is ▁said ▁to ▁have ▁expressed ▁regret ▁that ▁he ▁had ▁not ▁enough ▁time ▁to ▁conquer ▁Bal ag uer ▁and ▁L le ida . ▁A ▁small ▁monument ▁has ▁been ▁ere cted ▁to ▁Arn au ▁at ▁For ad ada ▁near ▁Mont son ís . ▁ ▁Notes ▁ ▁S ources ▁ ▁Cal vo , ▁Ric ardo . ▁" The ▁Old est ▁Ch ess ▁Pie ces ▁in ▁Europe ." ▁December ▁ 2 0 0 1 . ▁Fernández , ▁Ja ume . ▁" Ar n au ▁Mir ▁de ▁T ost : ▁El ▁C id ▁de ▁les ▁Ter res ▁de ▁L le ida ." ▁Person at