[5] During the reign of King Casimir III the Great, Oleśnica was the seat of a Roman Catholic parish, which covered the area of 49 square kilometers.

Oleśnica received Magdeburg rights in the year 1470, and during the Polish Golden Age, it was a small town, with 12 artisans.

Furthermore, since the mid-16th century, it was a local center of the Protestant Reformation, with a Calvinist prayer house, opened here in 1563 by Mikolaj Zborowski.

Due to proximity of the tightly locked Austrian–Russian border, Oleśnica's development was halted, and finally, after the January Uprising, it lost the town charter.

Among them were Dobieslaw Oleśnicki, the castellan of Wojnicz, Lublin and Sandomierz, the starosta of Kraków, who participated in the Battle of Grunwald and commanded the siege of the Malbork Castle in 1410, and Cardinal Zbigniew Olesnicki, the Bishop of Krakow in 1423–1455, as well as many members of the Zborowski family.