At no time during the Byzantine period was the entire area within the city walls built up completely, for it is known that there were open spaces within the city. Odon de Deuil, a traveller who visited the city in 1147, states that there were gardens, orchards and fields within the city walls that were capable of supplying its inhabitants with food. According to this traveller, the inside of the city was 'extremely dirty, disgusting, and full of filth; there are even such places to which daylight does not penetrate and under the cover of the darkness that reigns murders and other foul deeds can easily be perpetrated."

To put it in a nutshell, Odon de Deuil considered that the city was "disproportionate in all ways". At about the same time the city was visited by Benjamin, a rabbi from the city of Tudela in Spain. After mentioning the priceless treasures to be found in the city and its palaces and the pomp and wealth of its inhabitants, he then refers to the condition of the Jewish community in the city, saying that its filth was used as a way of insulting the Jews. In the year 1220 Anton, bishop of Novgorod in Russia, who was going on a pilgrimage, visited Istanbul. He paid individual visits to

its churches and monasteries and in his manuscript makes long and detailed lists of the sacred objects and treasures in these places; at the same time he provides valuable information about the town planning concept of that period. At that time there were long streets with columns on either side, known as ~embolos', which were set aside for the use of certain persons, tradesmen's and craftsmen's guilds. The European knights leading the Fourth Crusade managed to capture Byzantium in 1204 by taking advantage of the intrigues centering around the throne. They plundered the city, considering this to be a more profitable pastime than fighting the Muslims in Palestine and Syria.

When they entered the city Geoffroy de Villehardouin, a French knight who was one of the commanders of the army, stated that "it was impossible to find a person who would not be stirred by the sight," going on to dwell upon the beauty, magnificence and wealth of the city. He then says that all of these magnificent places were badly damaged by the fire that raged for two days and two nights during the battle that took place for the possession of the city. "It is impossible to calculate the damage done, to count the cost of a fortune turned to ashes," says the knight. Robert de Clan, one of the poor knights who took part in the same crusade, states that while the crusaders of the highest rank invaded the palaces and mansions of the city's wealthy families those of more humble rank such as himself contented themselves with plundering the homes of its more modest inhabitants. "As the city is very big and crowded there was something for everybody, and even to spare," he concluded.

The Latin invasion, which lasted from 1204 to 1261, was a disaster for Istanbul in the full sense of the word. Graves were plundered , churches and monasteries ransacked. The atrocities committed by the European knights, who had set out with the aim of fighting the Muslims and recapturing places that were sacred to Christians, the damage they did to Ayasofia, a Christian place of worship and the bestial acts to which the women and girls of the city were subjected are all described in detail by the historians of the period. Fifty years of Latin rule was sufficient to reduce the city to ruins.

In any case, due to the fact that during the seige of 1203-1204 more than half the city had been destroyed by fire and most of its Byzantine population had left,when it was finally recaptured by the Byzantincs in 1261 it proved impossible to rebuild the city and restore it to its former glory. The Byzantine emperor Mikhael VIII tried to persuade the people to return to the city after 1261 but all his efforts proved in vain. In place of the ruined streets that had formerly been lined with columns he had tree~lined roads built.