Both Chalkokondyles and Kritoboulos state that his Grand Vizier, Mahmud Pasha Angelovic, arrived one day before the Sultan, and began the negotiations for surrender. Where Chalkokondyles and Kritoboulos differ is the role that George Amiroutzes, the protovestiarios of Trebizond, played in these negotiations. Chalkokondyles states that Mahmud Pasha negotiated with David through George Amiroutzes, whom Chalkokondyles describes as the Pasha's cousin;[37] Kritoboulos omits all mention of Amiroutzes in these negotiations, stating that Mahmud Pasha sent as a messenger Thomas, the son of Katabolenos, to offer Emperor David this choice.[38]