The piratical seizure of Constantinople by the Latins brings in view the French and Venetians, the family of Courtenay and its pleasant digression.

Then comes the slow agony of the restored Greek empire.

Threatened by the Moguls, it is invaded and dismembered by the Ottoman Turks.

Constantinople seems ready to fall into their hands.

But the timely diversion of Tamerlane produces a respite of half a century.