All the descriptions of Constantinople in the fifteenth century, whether written by Greek natives or by Western travellers, bear witness to a state of exhaustion and debility which make us wonder that the empire did not collapse sooner. The country outside the walls was a desert. Within them more than half the ground was unoccupied, and covered only by ruins which testified to ancient magnificence. The great palace by the Augustaeum, which sheltered so many generations of emperors, had grown so dilapidated that the Paleologi dwelt in a mere corner of it. Part of the porticoes of St. Sophia had fallen down, and the Greeks could not afford to repair even the greatest sanctuary of their faith. The population of the city had shrunk to about a hundred thousand souls, most of them dwelling in great poverty. Such commerce and wealth as still survived in Constantinople had passed almost entirely into the hands of the Italians of Genoa and Venice, whose fortified factories at Galata and Pera now contained the bulk of the wares that passed through the city. The military strength of the empire was composed of about four thousand mercenary troops, of whom many were Franks and hardly any were born subjects of the empire. The splendid court, which had once been the wonder of East and West, had shrunk to such modest dimensions that a Burgundian traveller noted with surprise that no more than eight attendants accompanied the empress when she went in state to worship in St. Sophia.(32) John VI., in spite of the caution with which he avoided all action, was destined to see the empire lose its most important possession beyond the walls of Constantinople. His brother Andronicus, governor of Thessalonica, traitorously sold that city to the Venetians for 50,000 zecchins. The Sultan, incensed at a transfer of Greek territory having taken place without his permission, pounced down on the place, expelled the Venetians and annexed Thessalonica to the Ottoman Empire [1430].