Sigismund I.'s successor, the cultured and to some extent liberal-minded Sigismund II. Augustus (1548-1572), followed in his relations with the Jews the same principles of toleration and non-interference by which he was generally guided in his attitude towards the non-Christian and non-Catholic citizens of Poland. In the first year of his reign Sigismund II., complying with the request of the Jews of Great Poland, ratified, at the general Polish Diet held at Piotrkov, the old liberal statute of Casimir IV. In the preamble of this enactment the King declares that he confirms the rights and privileges of the Jews on the same grounds as the special privileges of the other estates, in other words, by virtue of his oath to uphold the constitution. Sigismund Augustus considerably amplified and solidified the self-government of the Jewish communities. He bestowed large administrative and judicial powers upon the rabbis and Kahal elders, sanctioning the application of "Jewish law" (_i. e._ of Biblical and Talmudical law) in civil and partly even criminal cases between Jews (1551). In the general voyevoda courts, in which cases between Jews and Christians were tried, the presence of Jewish "seniors," _i. e._ of duly elected Kahal elders, was required (1556). This liability of the Jews to the royal or voyevoda courts had long constituted one of their important privileges, since it exempted them from the municipal, or magistrates' courts, which were just as hostile to them as the magistracies themselves. This prerogative--the guarantee of greater impartiality on the part of the royal court--was limited to the Jews residing in the royal cities and villages, and did not extend to those living on the estates of the nobles or in the townships owned by them. Sigismund I. had decreed that "the nobles having Jews in their towns and villages may enjoy all the advantages to be derived from them, but must also try their cases. For we [the King], not deriving any advantages from such Jews, are not obliged to secure justice for them" (1539). Sigismund Augustus now enacted similarly that the Jews living on hereditary Shlakhta estates should be liable to the jurisdiction of the "hereditary owner," not to that of the royal representatives, the voyevoda and sub-voyevoda. As for the other royal privileges, they were extended to the Jews of this category only on condition of their paying the special Jewish head-tax to the King (1549). The split between royalty and Shlakhta, which became conspicuous in the reign of Sigismund Augustus, had already begun to undermine the system of royal patronage, more and more weakened as time went on.