The Crown Sejm in the Jagiellonian Era (1386-1572). The birth, development, "golden age"

The birth of parliamentarism in the Kingdom of Poland, its development, and its heyday, referred to in historiography as the ‘golden age’, are associated with the almost two-hundred-year reign of the Jagiellonian dynasty (1386–1572). During the reign of four generations of Jagiellons, the oligarchic monarchy of the fifteenth century was transformed into a parliamentary monarchy of nobles in the next century. One of the institutional foundations and principles of the state was the two-tier parliamentary system, which ensured actual participation in power of the holders of political rights. The year 1468 saw the birth of the Chamber of Deputies, based on the principle of representation, and consequently, the establishment of the bicameral Crown Sejm. The Polish-Lithuanian Union concluded in Lublin in 1569 resulted in legal and political decisions which determined the role and functioning of the Sejm until the collapse of the Commonwealth at the end of the eighteenth century