 The legal pronouncements, intended to facilitate the functioning of a uniform and centralized state, with ordinary "szlachta" privileges strongly protected, were frequently ignored by the kings, beginning with Sigismund I, and the upper nobility or church interests.This situation became the basis for the formation around 1520 of the "szlachta"'s execution movement, for the complete codification and execution, or enforcement, of the laws.In 1518 Sigismund I married Bona Sforza d'Aragona, a young, strong-minded Italian princess.