Complex sentence: In 1327 Kazimierz I, Duke of Cieszyn, swore homage to the Bohemian king John of Luxembourg, and the duchy became an autonomic fiefdom of the Bohemian crown.
Split into simpler sentences: In 1327 Kazimierz I, Duke of Cieszyn, made a homage to the Bohemian king John of Luxembourg. Since then, Duchy became an autonomic fiefdom of the Bohemian crown.