It was only in the age of chivalry, that valor could ascend from a private station to the thrones of Jerusalem and Constantinople. The titular kingdom of Jerusalem had devolved to Mary, the daughter of Isabella and Conrad of Montferrat, and the granddaughter of Almeric or Amaury. She was given to John of Brienne, of a noble family in Champagne, by the public voice, and the judgment of Philip Augustus, who named him as the most worthy champion of the Holy Land. [40] In the fifth crusade, he led a hundred thousand Latins to the conquest of Egypt: by him the siege of Damietta was achieved; and the subsequent failure was justly ascribed to the pride and avarice of the legate. After the marriage of his daughter with Frederic the Second, [41] he was provoked by the emperor's ingratitude to accept the command of the army of the church; and though advanced in life, and despoiled of royalty, the sword and spirit of John of Brienne were still ready for the service of Christendom. In the seven years of his brother's reign, Baldwin of Courtenay had not emerged from a state of childhood, and the barons of Romania felt the strong necessity of placing the sceptre in the hands of a man and a hero. The veteran king of Jerusalem might have disdained the name and office of regent; they agreed to invest him for his life with the title and prerogatives of emperor, on the sole condition that Baldwin should marry his second daughter, and succeed at a mature age to the throne of Constantinople. The expectation, both of the Greeks and Latins, was kindled by the renown, the choice, and the presence of John of Brienne; and they admired his martial aspect, his green and vigorous age of more than fourscore years, and his size and stature, which surpassed the common measure of mankind. [42] But avarice, and the love of ease, appear to have chilled the ardor of enterprise: [421] his troops were disbanded, and two years rolled away without action or honor, till he was awakened by the dangerous alliance of Vataces emperor of Nice, and of Azan king of Bulgaria. They besieged Constantinople by sea and land, with an army of one hundred thousand men, and a fleet of three hundred ships of war; while the entire force of the Latin emperor was reduced to one hundred and sixty knights, and a small addition of sergeants and archers. I tremble to relate, that instead of defending the city, the hero made a sally at the head of his cavalry; and that of forty-eight squadrons of the enemy, no more than three escaped from the edge of his invincible sword. Fired by his example, the infantry and the citizens boarded the vessels that anchored close to the walls; and twenty-five were dragged in triumph into the harbor of Constantinople. At the summons of the emperor, the vassals and allies armed in her defence; broke through every obstacle that opposed their passage; and, in the succeeding year, obtained a second victory over the same enemies.