The "magister" was first given command of the palace guard, the "Scholae Palatinae". He was also appointed head of the palatine secretariats, divided into four bureaux, the "sacra scrinia", each under a respective "magister": the "scrinium memoriae", the "scrinium epistularum", the "scrinium libellorum" and the "scrinium epistolarum Graecarum". The first bureau handled imperial decisions called "annotationes", because they were notes made by the emperor on documents presented to him, and also handled replies to petitions to the emperor. The second handled correspondence with foreign potentates and with the provincial administration and the cities, the third dealt with appeals from lower courts and petitions from those involved in them, and the fourth handled the documents issued in Greek and the translation of Latin documents into Greek. Constantine also transferred the supervision of the "agentes in rebus", a corps of trusted messengers who also functioned in a bureaucratic role as monitors of the imperial administration, to the "magister". Control of the feared "agentes", or "magistriani" as they were also known, gave the office great power.