Since the time of his birth, Wenceslaus III Adam was placed under the guardianship of his grandfather Casimir II, Duke of Cieszyn as his only heir,[1] until his death four-year later, in 1528.

In his will, Duke Casimir II left his Duchy to his grandson under the regency of his mother Anna and the Bohemian magnate Jan, Baron of Pernštejn and Count of Kłodzko, called "The Rich".

Despite this, Jan of Pernštejn remained as a regent and held the effective government until 9 May 1545, when he finally renounced to the regency only in exchange of the lands of Místek and Friedland as a pledge.

Under the rule of Wenceslaus III Adam, Cieszyn economy was stabilized and even developed, despite the fact that during the period of regency were lost the Upper Silesia lands gained during the reign of Casimir II and the Duchy of Opava.

As a young prince Wenceslaus III Adam was educated in the medical science, dealing with the care of patients, which gained special significance during the epidemic of 1570.

In foreign policy, despite his conversion to Lutheranism, Wenceslaus III Adam based his career in the faithful service to the House of Habsburg in Vienna.

Another big problem for the Duke was the prodigality of his oldest son, Frederick Casimir, who was named ruler over Fryštát and Skoczów in 1560, and five years later, he also received Bielsko.