The Rus' princes had to receive a patent for his throne from the khan, who then sent an envoy to install the prince on his throne. From the time of Öz Beg Khan on, a commissioner was appointed by the khan to reside at each of the Rus' principalities' capitals. Mongol rule loosened in the late 13th century so that some Rus' princes were able to collect taxes as the khan's agents. By the early 14th century, all the grand dukes were collecting taxes by themselves, so that the average people no longer dealt with Mongol overlords while their rulers answered to Sarai.