- Z ub ay r . ▁ ▁Abd ▁al - Mal ik ▁is ▁cred ited ▁with ▁central izing ▁the ▁administration ▁of ▁the ▁C ali ph ate ▁and ▁with ▁establish ing ▁Arab ic ▁as ▁its ▁official ▁language . ▁He ▁also ▁introduced ▁a ▁uniqu ely ▁Muslim ▁coin age , ▁marked ▁by ▁its ▁an icon ic ▁decor ation , ▁which ▁supp l anted ▁the ▁By z antine ▁and ▁S as an ian ▁co ins ▁that ▁had ▁previously ▁been ▁in ▁use . ▁Abd ▁al - Mal ik ▁also ▁recom men ced ▁off ensive ▁war fare ▁against ▁By z ant ium , ▁defe ating ▁the ▁By z ant ines ▁at ▁Sebast opol is ▁and ▁recover ing ▁control ▁over ▁Armen ia ▁and ▁C au cas ian ▁I ber ia . ▁Following ▁Abd ▁al - Mal ik ' s ▁death , ▁his ▁son , ▁Al - W al id ▁I ▁( 7 0 5 – 7 1 5 ), ▁became ▁cal i ph . ▁Al - W al id ▁was ▁also ▁active ▁as ▁a ▁builder , ▁spons oring ▁the ▁construction ▁of ▁Al - M as j id ▁al - N ab aw i ▁in ▁Med ina ▁and ▁the ▁Great ▁Mos que ▁of ▁Dam asc us . ▁ ▁During ▁the ▁reign ▁of ▁al - W al id , ▁the ▁Um ay y ads ▁conquer ed ▁nearly ▁the ▁entire ty ▁of ▁the ▁I ber ian ▁Pen ins ula ▁( except ▁for ▁the ▁northern most ▁Christian ▁kingdom ▁of ▁Ast ur ias ) ▁under ▁the ▁military ▁leadership ▁of ▁T ari q ▁ibn ▁Z iy