 Acting as the head of the other princes, the "ishkhan" was answerable to the Arab governor, being responsible for the collection of the taxes owed to the caliphal government and the raising of military forces when requested.A census and survey of "Arminiya" was undertaken , followed by a significant increase in taxation so as to finance the Caliphate's increasing military needs in the various fronts.The Armenians participated with troops in the hard-fought campaigns of the Second Arab–Khazar War in the 720s and 730s.