The results of the Fourth Crusade were as fatal for the Byzantine Empire as for the future of the crusades. The Empire could never recover from the blow inflicted on it in 1204; it lost forever the significance of a political world power. Politically, the Eastern Empire, as a whole, ceased to exist; it yielded its place to a number of west European feudal states and never again, even after the restoration of the Empire under the Palaeologi, did it regain its former brilliancy and influence.
As regards the significance of the Fourth Crusade for the general problem of the crusading movement, it showed, first of all, in the clearest way that the idea of the movement had become entirely secular; secondly, it bifurcated the single motive which had formerly drawn the western peoples to the East. After 1204 they had to direct their forces not only against the Muslims in Palestine or Egypt, but, on a larger scale, to their own new possessions on the territory of the Eastern Empire in order to support their power there. The result of this, of course, was to delay the struggle against the Muslims in the Holy Land
The Fourth Crusade and Byzantium 
