Senat. The most important such officials were the Great Secretaries (singular: sekretarz wielki), Crown and Lithuanian. Only a man of the cloth could be a Great Secretary. These functionaries were considered more consequential than any district or court official, with the exception of the Court Marshal. They could act as Chancellors when no Chancellor was in attendance. They dealt with secret letters; in Senat they read out letters of the King's and resolutions of the Sejm. The Great Secretaries often acted as Assessors and were called "innate Assessors." Next were 4 Referendaries (singular: referendarz), 2 secular and 2 ecclesiastic, one each for the Crown and for Lithuania. They rarely left the royal court, and their duties consisted in hearing petitions and complaints, which they referred (hence their name) to the King. They also acted as judges in cases involving peasants from the King's lands, and often acted as Assessors at other courts. Close to the office of Referendary was that of the "Instygator"—what today would be termed a State Prosecutor. One each for Crown and for Lithuania, the Instygators were tasked with uncovering and dealing with crimes against the King and the country, and were authorized to prosecute any dignitary save the King. They had deputies known as "viceinstygators." Then came the Great Writers (singular: pisarz wielki)—one for the Crown, three for Lithuania. It was their task to clarify royal decrees and send letters to those dignitaries who must hear of them. They often acted as ambassadors and Assessors. The Crown Keeper (kustosz koronny) was the official responsible for safeguarding the Royal Treasury, where the royal insignia were kept. The keys to the Treasury were held by the Great Treasurer and six voivods, and without each of them, the Treasury could not be opened. Traditionally, the Crown Keeper was chosen from among the priests of Kraków Cathedral. The Lithuanian Keeper was actually called a Treasurer (skarbny). From 1647, the ministers were joined by a Postmaster General (Poczmistrz generalny, also known as Poczmistrz naczelny or Generał poczmistrz), the supervisor of the Royal Post, founded in 1547. In principle, Polish–Lithuanian officials enjoyed life tenure. Of several notable exceptions to that rule, the most important involved the Senat Marshal, who chaired Senat meetings and could suggest, but not determine, the subject of a meeting. Traditionally, the post of Senat Marshal rotated among Senators from the three prowincyje ("provinces" – major divisions) of the