Between what two centuries were the Szlachta pirveleges, which formed the cornerstone of the Polish political system, granted?
Szlachta privileges: The privileges of the "szlachta" (Poland's nobility) formed a cornerstone of "Golden Liberty" in the Kingdom of Poland and, later, in the Polish-Lithuanian Commonwealth. Szlachta privileges:  Most of the privileges were granted between the late 14th and early 16th centuries.
i don't know