Niketas Choniates's account of the devastating fire of August 1203
And, indeed, after taking up positions in a goodly number of locations, they set fire to the buildings. The flames rose unbelievably high above the ground throughout that night, the next day, and the followinf evening as they spread everywhere. It was a novel sight, defying the power of description. While in the past many conflagrations had taken place in the City - no one could cite how many and of what sort they had been - the fires ingnited at this time proved all the others to be but sparks. The flames divided, took many different directions and then came together again, meandering like a river of fire. Porticoes collapsed, the elegant structures of the agorae toppled, and huge columns went up in smoke like so much brushwood. Nothing could stand before those flames. Even more extraordinary was the fact that burning embers detached themselves from this roaring and raging fire and consumed buildings at a great distance. Even more extraordinary was the fact that burning embers detached themselves from this roaring and raging fire and consumed buildings at a great distance. Shooting out at intervals, the embers darted through the sky, leaving a region untouched by the blaze, and then destroying it when they turned back and fell upon it. The fire, advancing for the most part in a straight course driven by a north wind, was soon observed to turn aside as though fanned by a south wind, to move aslant, turning this way and that way as it unexpectedly charred and burned everything. Even the Great Church was endangered.
Niketas Choniates, Historia [ed. J. van Dieten, pp. 553-4], transl. by H. J. Mangoulias, O city of Byzantium: annals of Niketas Choniates (Detroit 1984), pp. 303.