Preserved interstate treaties and other documents from the 12th century show that the authorities would already oversee the work of the public notary and the chancellery. Based on key provisions made during the 15th century, the central administration consisted of five offices located in the Rector's Palace. These were: The Public Notary (legal private affairs), the State Chancellery (legal public affairs), the Judicial Chancellery Office (criminal justice affairs), the Office of the State Secretary (legal state affairs) and the Slavic Chancellery, which would eventually be transformed into the Turkish Chancellery. The secretaries oversaw the process of taking minutes of the sessions of the Major Council, the Senate, as well as of those of the Minor Council. In addition, secretaries would also compile the entire state correspondence as instructed by the Senate and the Minor Council. They also created diplomatic codes and deciphered diplomatic mail, and issued state documents, such as certificates of the citizenship of the Dubrovnik Republic. The influence of secretaries increased so much since the 17th century, that they could be considered as the main administrative officials of the Dubrovnik Republic.