continued their rule in the Balkans (Rumelia), Bosnia was somewhat relieved of the pressures of being a frontier province, and experienced a period of general welfare. A number of cities, such as Sarajevo and Mostar, were established and grew into regional centers of trade and urban culture and were then visited by Ottoman traveler Evliya Çelebi in 1648. Within these cities, various Ottoman Sultans financed the construction of many works of Bosnian architecture such as the country's first library in Sarajevo, madrassas, a school of Sufi philosophy, and a clock tower (Sahat Kula), bridges such as the Stari Most, the Tsar's Mosque and the Gazi Husrev-beg's Mosque.
Furthermore, some Bosnians played influential roles in the Ottoman Empire's cultural and political history during this time. Bosnian recruits formed a large component of the Ottoman ranks in the battles of Mohács and Krbava field, while numerous other Bosnians rose through the ranks of the Ottoman military to occupy the highest positions of power in the Empire, including admirals such as Matrakçı Nasuh; generals such as Isa-Beg Isaković, Gazi Husrev-beg and Telli Hasan Pasha; administrators such as Ferhat-paša Sokolović and Osman Gradaščević; and Grand Viziers such as the influential Mehmed Paša Sokolović. Some Bosnians emerged as Sufi mystics, scholars such as Ali Džabič; and poets in the Turkish, Albanian, Arabic, and Persian languages.
However, by the late 17th century the Empire's military misfortunes caught up with the country, and the conclusion of the Great Turkish War with the treaty of Karlowitz in 1699 once again made Bosnia the Empire's westernmost province. The following century was marked by further military failures, numerous revolts within Bosnia, and several outbursts of plague. The Porte's false efforts at modernizing the Ottoman state were met with distrust growing to hostility in Bosnia, where local aristocrats stood to lose much through the proposed reforms
