After subjugating of the region of Takovo, the conquerors introduced their feud-military system or the system of landed estates. From the Northern parts of the former Serbian Despotic that were finally conquered in 1458 and 1459, the Turks made the Sanjak of Smederevo which also included the areas around Takovo.
Considering the strategic importance of Ostrvica and Rudnik, the Turks placed their garrison in those places. Rudnik together with Ostrvica became the center of feud-military and administrative organization of this whole region.
One of the five districts of Sanjak of Smederevo was Ostrvica District (or Rudnik District).
"District of Ostrvica (Suviridze Hisar in Turkish)or District of Rudnik was established right after the fall of this distinguished fortress and the most important mining center in Sumadija to the Turks in 1458. The first name was given to it because it was not only the name of the most important fortress in this area but it was also the name of Medieval Parish. It got its second name because the center of this District was constantly in Rudnik as it was the main mining and economic center of Ostrvica Parish, mentioned for the first time in 1458 just before the fall of this region to the Turks".
Very interesting notes from the XVII century were left to us by the well-known Turkish travel writer Evlia Chelebia who crisscrossed the whole region of Takovo at that time. For Rudnik he says that it was a backwater town in the spacious plain surrounded by gardens and vineyards. There was an awful ravine .It was the place where the climate was leaden and the sun was scanty.
According to the description of Evlia Chelebia, Rudnik then (in 1664) was the town of 800 shingle roofed houses, the town of seven Muslims and Non-Muslim wards and eleven places of worship; it had 3 primary schools and one dark hammam. Then he also says that Jasenica river set a great number of mills in motion. The inhabitants were the Serbs and newcomers, very respected and wealthy and that they all spoke Turkish. Most of them were traders. There were 80 shops in the town. The population was healthy and they always ate heartily because of good quality of cold water and food. Chelebia notices that the fortress had already, been neglected then, so the shepherds kept their cattle in it during the winter time.