The szlachta were not fond of him or the oligarchy he stood for, and made it clear to Władysław Jagiełło that he needed their support as well as that of the magnates in order to secure the succession of his son. This enabled them to extort a number of privileges and rights during the 1420s, the most important of which, granted at Jedlnia in 1430 and confirmed at Kraków three years later, was the edict
Hemmed in by the magnates, Kazimierz IV sought the support of the szlachta, which was eager to give it, at a price. The price was the Privilege of Nieszawa, granted in 1454, which stipulated that the king could only raise troops and taxes with the approval of the district assemblies, the sejmiks (lesser sejms) of the eighteen palatinates of Poland. This enshrined the principle of no taxation without representation for the ordinary szlachta, who all had a vote at these assemblies, but it also made the sejms of Wielkopolska and Małopolska more directly answerable to their electorate. In 1468, these decided to meet together, at Piotrków, and henceforth constituted the national Sejm, bringing together dignitaries of the kingdom, and the representatives of all the provinces and the major towns (Lithuania was still ruled autocratically by the grand duke, and Mazovia, ruled by a vassal Piast, kept its own separate sejm for another century). The next step came in 1493, when the national assembly divided into two chambers: the Senate, consisting of eightyone bishops, palatines and castellans, and the Sejm proper, which consisted of fifty-four deputies of the szlachta and the largest cities.
The death of Kazimierz IV in the previous year afforded the new parliament an opportunity to flex its muscles and demonstrate that the existence of a natural heir to the throne did not infringe its right to choose who would rule over them. For two weeks the Sejm discussed the merits of a number of candidates, including the king’s sons and a Piast prince from the Mazovian line, and finally chose Kazimierz’s son, Jan Olbracht.
From now on not even the only son of the deceased king would sit on the Polish throne before being vetted by the Sejm. After the death of Jan Olbracht in 1501 his brother Aleksander was elected, and forced to sign over yet more royal power before he could take his throne. Four years later, in 1505, the Sejm sitting at Radom passed the act
The constitutional developments of the fifteenth century are mirrored in the legal system. The regional castellans’ courts had declined steadily in influence. Their jurisdiction was encroached upon by the starostas’ courts, which dealt with the affairs of the szlachta and their tenantry, elective courts, whose judges were appointed by the regional sejmiks, and, most of all, by the ecclesiastical courts. The latter, which originally governed those living on Church-owned lands, gradually extended their com petence to cover all cases involving a cleric or Church property, as well as those with a religious dimension (marriages, divorces, sacrilege, etc.). The division of the country allowed the ecclesiastical courts to encroach on other areas, by providing what was in effect an independent legal system embracing the whole country, which proved convenient in cases where the litigants were residents of different provinces. They complemented the rising power of the Church hierarchy, and directly challenged the influence of the central legal system. This was reinforced through the new county courts (