Emperor John IV of Trebizond was aware of the threat Mehmed II posed for him at least as early as February 1451, when the Byzantine diplomat George Sphrantzes arrived in Trebizond seeking a bride for his emperor, Constantine XI. John had happily related to the visiting diplomat the news of the death of Sultan Murad II, and that Mehmed II's youth meant that now his empire could last longer and be blessed. Sphrantzes, however, was taken aback and explained to him that Mehmed's youth and seeming friendship were only ploys, and that Mehmed was more of a threat to both monarchies than his father had been.[12]