The son of Wacław III and his wife, Maria of Pernątejn. His father apportioned to him the Frydek and Frysztat districts in 1560, followed by Bielsko in 1565. His spendthrift lifestyle caused him to incur significant debts on his inheritance. He died during a stay in Bohemia, and was buried alongside the grave of his mother in Pardubice.
      On 28 December 1563 Prince Fryderyk Kazimierz married Katarzyna (* 7 February 1542 + 3 September 1569), the daughter of the Prince of Legnica, Fryderyk III and Catherine of Meklemburg. Fryderyk Kazimierz and Katarzyna had one daughter, also named Katarzyna. They ruled Bielsko together, living a profligate life and borrowing heavily. The princely couple compelled the townspeople of Bielsko and Cieszyn to guarantee the aforementioned loans.

(F. W. Sommersberg, vol. 1, p. 740, M. Kasperlik, Friedrich Kasimir, p. 76 ff.)