also aided the treasury by implementing strict military rolls, thereby preventing soldiers from collecting the salaries of their deceased comrades. He also proclaimed a general military mobilization of Muslim subjects and drafted Kurdish and Yörük tribesmen, thus increasing the number of conscripts. Other reforms eased the burden of the Empire's non-military subjects. Köprülü Fazıl Mustafa Pasha reformed the poll tax, paid by the empire's non-Muslim subjects, by restoring the policy of having taxes collected on individual adults (instead of collective assessment, which harmed communities whose populations had decreased due to war and other factors). Fazıl Mustafa Pasha also made it easier to issue permits to fix or rebuild Christian churches. Having suffered from factionalism in the court and government, Fazıl Mustafa Pasha attempted to limit the number of viziers in the imperial council. To combat the abuse of power of local and regional authorities, he set up councils of notables in the provinces, modeling these on the imperial government. The far-reaching effects of his administrative reforms would last for decades. Military successes, disaster, and death The course of the ongoing Great Turkish War worsened when Russia began its involvement and formally joined an alliance of European powers by launching the devastating Crimean campaigns. Under Fazıl Mustafa Pasha's leadership the Ottomans halted an Austrian advance into Serbia and crushed an uprising in Bulgaria. Fazıl Mustafa Pasha's 1690 campaign brought further success, with the recapture of Niš, Vidin, Smederevo, and Golubac. He then besieged Belgrade, using 40,000 infantry and 20,000 cavalry. On 8 October, after the defenders’ armory was destroyed in an explosion, the Habsburg commander capitulated. The recapture of Belgrade, originally conquered by the Ottomans in 1521 but lost to the Habsburgs in 1688, gave hope to the Ottomans that their military disasters of the 1680s, including the losses of Hungary and Transylvania, could be reversed. The hope proved deceptive. On 19 August 1691, Fazıl Mustafa Pasha was struck in the forehead by a bullet at the Battle of Slankamen (northwest of Belgrade). The Ottomans suffered a devastating defeat at the hands of Ludwig Wilhelm von Baden, the commander-in-chief of the Imperial Army in Hungary, nicknamed "Türkenlouis" (Louis the Turk) for his victories. Called "the bloodiest battle of the century" by contemporaries, the defeat at Slankemen cost the lives of 20,000 men and the Ottoman's most capable military commander. Fazıl Mustafa Pasha was the fifth member of the Köprülü family to