During the 1660s and 1670s, the Ottoman Empire reached the peak of its expansion with military invasions of Ukraine and Habsburg Hungary, parts of central Europe that had traditionally been regarded as beyond the Porte's horizons. Many Ukrainians and Hungarians welcomed the Ottomans as liberators; they saw the sultan as a more benevolent ruler than the Russian tsar, the Polish king, and the Habsburg emperor. This article reconstructs the political, social, and religious dimensions of pro-Ottoman hopes as well as the popular revolts that resulted from these hopes. Comparing Ukrainian and Hungarian engagements with the Ottomans reveals the divergent and overlapping aspects of a largely forgotten historical reality, that is, the quest of many Orthodox and Protestant Europeans to consider a Muslim alternative to the Christian empires that oppressed them. The article draws on a treasure trove of little studied sources, both archival and published, in multiple languages.