Thereupon, in 1422, siege was laid to Constantinople. The walls had largely fallen out of repair and the three thousand men who were sent as a first detachment sat down before it in hope of an easy capture. A few days later Murad himself appeared, bringing with him in chains the Greek ambassadors who had been sent to treat of peace. A large army of two hundred thousand men, together with a great crowd of bashi-bazouks, encamped before the landward walls and built an earthwork for their protection from the Golden Gate to the Xyloporta at the end of the walls on the Golden Horn. Among them, or arriving shortly afterwards, was a certain Mersaite, a Madhi, a half-mad fanatic at the head of five hundred dervishes. He claimed to be of the blood of Mahomet and to possess prophetic powers. He foretold that the capture of the city would happen when he gave the signal, for which all were to be ready. The sultan had sat down before the walls in the middle of June, but his primitive bombs, his wooden towers, and his attempts to undermine the walls were of no avail. Mersaite prophesied a capture on August 24. On that day the defenders of the foss were rained upon with showers of arrows and a general assault was made, but the two Theodosian walls, which were defended by crowds of citizens, were far too strong to be captured by the simple fanatical onslaught of dervishes. The Greeks fought valiantly, the young Emperor John being at their head and on horseback, in the peribolos outside the Romanus Military Gate, formerly knowm as the Pempton. Upon the failure of the attack by the dervishes, Murad suddenly raised the siege and the Greeks pursued the retreating army and captured some of their rude guns.[101] The immediate cause of the raising of the siege of Constantinople is variously stated. Manuel had sent aid to the adherents of Mustafa, the younger brother of Murad, aged only six years, and had thus strengthened the revolt which had been raised in his favour in Asia Minor. It was of more importance to Murad to put an end to this Turkish rising than to persist in his attempt to capture the city.[102] [Sidenote: Death of Manuel, 1425.] In 1425 Manuel, whom Ducas describes not incorrectly as a wise and moderate prince, died, after a reign of thirty-four years. [Sidenote: John, 1425–1448.]