Complex sentence: The military aspect set it back some when it was included in the Military Frontier in the 16th century during the wars with the Ottoman Turks, but after Maria Theresa's decree of 1765 it resumed life as a peaceful little merchant town.
Split into simpler sentences: The military aspect set it back when it was included in the Military Frontier in the 16th century during the wars with the Ottoman Turks. After Maria Theresa's decree of 1765, however, it resumed life as a peaceful little merchant town.