a great slaughter of Christians through the city". According to historian Philip Mansel, widespread persecution of the city's civilian inhabitants took place, resulting in thousands of murders and rapes, and 30,000 civilians being enslaved or forcibly deported. George Sphrantzes says that people of both genders were raped inside Hagia Sophia. Since the time of the Austro-Turkish war (1683–1699), relations between Muslims and Christians who lived in the European provinces of the Ottoman Empire gradually deteriorated and this deterioration in interfaith relations occasionally resulted in calls for the expulsion or extermination of local Christian communities by some Muslim religious leaders. As a result of Ottoman oppression, the destruction of Churches and Monasteries, and violence against the non-Muslim civilian population, Serbian Christians and their church leaders, headed by Serbian Patriarch Arsenije III, sided with the Austrians in 1689 and again in 1737 under Serbian Patriarch Arsenije IV. In the following punitive campaigns, Ottoman forces conducted systematic atrocities against the Christian population in the Serbian regions, resulted in the Great Migrations of the Serbs. Ottoman Albania and Kosovo Before the late 16th century, Albania's population remained overwhelmingly Christian, despite the fact that it was under Ottoman rule, unlike the populations of other regions of the Ottoman Empire, such as Bosnia, Bulgaria and Northern Greece, the mountainous Albania was a frequent site of revolts against Ottoman rule, often at an enormous human cost, such as the destruction of entire villages. In response, the Ottomans abandoned their usual policy of tolerating Christians in favor of a policy which was aimed at reducing the size of Albania's Christian population through Islamization, beginning in the restive Christian regions of Reka and Elbasan in 1570. The pressures which resulted from this campaign included particularly harsh economic conditions which were imposed on Albania's Christian population; while earlier taxes on the Christians were around 45 akçes a year, by the middle of the 17th century the rate had been multiplied by 27 to 780 akçes a year. Albanian elders often opted to save their clans and villages from hunger and economic ruin by advocating village-wide and region-wide conversions to Islam, with many individuals frequently continuing to practice Christianity in private. A failed Catholic rebellion in 1596 and the Albanian population's support of Austro-Hungary during the Great Turkish War, and its support of the Venetians in the 1644 Venetian-Ottoman War as well as the Orlov Revolt were all factors which led