 The town quickly developed, enjoying the support of the powerful "Wąchock Monastery", and in the late 15th century, it was larger than local urban centers of Radom and Iłża.In 1502, King Aleksander Jagiellończyk confirmed all privileges for Wierzbica, and in the mid-16th century, King Zygmunt II August extended them to the village of Rzeczków, located in the suburbs of the town.In the Polish Golden Age Wierzbica prospered, due to location on a local merchant route Opoczno – Skrzynno - Szydłowiec – Jastrząb – Wierzbica, with additional routes to Iłża, and Skaryszew.