During his reign the condition of the empire had undergone little change. Though when first associated with his father he had headed the war party, he recognised after the siege of the city in 1422 that his father’s dying counsel to keep on friendly terms with the Turks was wise. This policy, as we have seen, did not prevent him from doing all he could to obtain aid from the Western powers. He had paid the price which Rome exacted and never lost hope that such aid would come. At the same time he was ready to join with the Hungarians and other Christian nations, even at considerable risk of precipitating an attack upon the city. His power, however, was too small to make any co-operation outside the capital and the Straits of much value. He did what he could. He repaired and strengthened the city walls.[111] He kept the fleet in at least as good a condition as he had found it. He was probably justified in believing that his wisest course was to obtain all the aid possible from the West, to be ready to co-operate, and in the meantime to keep quiet. His pliant policy delayed the siege of the city and thus for a while averted the final calamity. CHAPTER VII PROGRESS OF TURKS BETWEEN 1391 AND 1425: SULTAN BAJAZED’S REIGN: CONQUESTS IN EUROPE: BULGARIAN KINGDOM ENDED: WESTERN ARMIES DEFEATED AT NICOPOLIS: ANATOLIA-HISSAR BUILT: CAPITAL THREATENED: SUMMONS BY TIMOUR TO BAJAZED: TIMOUR’S PROGRESS: REPLY OF BAJAZED: BATTLE OF ANGORA AND CRUSHING DEFEAT OF TURKS: FURTHER PROGRESS OF TIMOUR: DEATH OF BAJAZED, 1403: ALARM IN WESTERN EUROPE: DEPARTURE OF TIMOUR: STRUGGLE BETWEEN THE SONS OF BAJAZED: ULTIMATE SUCCESS OF MAHOMET: HIS GOOD UNDERSTANDING WITH MANUEL: DEATH OF MAHOMET, 1420: ACCESSION OF MURAD: WAR WITH EMPIRE: SIEGE OF CONSTANTINOPLE, 1422: DEATH OF MANUEL, 1425: TRIUMPHAL PROGRESS OF MURAD: HE BESIEGES AND TAKES SALONICA: BESIEGES BELGRADE BUT FAILS: COMBINED MOVEMENT UNDER HUNYADI AGAINST MURAD: BATTLE OF SLIVNITZA, 1443, AND DEFEAT OF TURKS: MURAD SUES FOR PEACE: TREATY MADE WITH LADISLAUS: VIOLATED BY CHRISTIANS: BATTLE OF VARNA, 1444: MURAD RAVAGES MOREA: ISKENDER BEY, HIS ORIGIN: CAPTURES CROIA: HUNYADI AGAIN ATTACKS MURAD: DEFEATED AT COSSOVO-POL, 1448: REASONS FOR FAILURE OF CHRISTIAN ATTEMPTS: JOHN HAS TO FOREGO JOINING WESTERN COMBINATION AGAINST TURKS: DEATH OF MURAD, 1451: MAHOMET THE SECOND BECOMES SULTAN.