The cathedral was consecrated in 1362/3 by the Patriarch Kallisto I, who also designated the Monastery as the Patriarchial Seat. During this period, the frescoes were created by a leading Byzantine artist, whose name has unfortunately not survived. Two portable icons of Christ Pantocratoras also date from this same period, one of which is in the sacristy of the Monastery, and the other in the Hermitage Museum in St Petersburg. In the border of the latter, at the lower right, the figure of the founder Ioannis the Primikerios is still preserved. The founders endowed the Monastery with many other works of art, objects and relics, some of which are still safeguarded with special care in the Monastery today.
