and conquests of Tamerlane the Tartar—The Turks defeated, and Syria overrun by the Tartars—Bajazet raises the siege of Constantinople, and is defeated by Tamerlane—Smyrna captured and destroyed—The Ottomans reconquer the provinces overrun by Tamerlane—The Greek Church submits to papal authority—The barbarities of the Turks towards the Christians—Pope Eugenius exhorts the Christian states to another crusade—Cardinal Julian preaches in its favour—Amurath enters into a treaty of peace with the Crusaders, which being violated, they are defeated with great slaughter—Ladislaus, king of Poland, and Cardinal Julian, slain—Battle of Warna—Accession of Mahomet II. to the Ottoman throne—His extensive empire—Besieges Constantinople—Character of Constantine Palæologus, the Greek emperor—His great efforts in defence of his capital—Mahomet takes the city by storm—Death of the emperor and destruction of the Greek empire pp. 92-158. BOOK XVII.—A.D. 1453-1481. CRUSADES AGAINST THE TURKS. Consternation among the Christian states at the fall of Constantinople.—Philip, duke of Burgundy, assembles his nobility at Lille—Curious festival held by—Enthusiasm in favour of a crusade against the Turks—Bishop Sylvius, John Capistran, Frederick III. of Germany, and Pope Calixtus III. endeavour to stir up the crusade—The Turks penetrate into Hungary—Valour of Hunniades—They are defeated at Belgrade—An alarming comet—Bishop Sylvius elected Pope—Extended conquests of Mahomet II.—He subdues Greece—The Pope convokes an assembly at Mantua to urge on the crusade—His negociations with Mahomet—Bosnia conquered—Pius II. engages personally in the crusade, reaches Ancona, and dies—Scanderberg defeats the Turks—Mahomet II. swears to annihilate Christianity—The king of Persia marches against the Turks, and his army is destroyed—Cardinal Caraffa commands a fleet of Crusaders—Satalia and Smyrna pillaged by the Christian forces—Possessions of the Venetians and Genoese captured by the Turks—Jacques Cœur—Cyprus subjected to the Mussulmans—Taken possession of by the Turks—Rhodes bravely defended by the knights of St. John—The Turks invade Hungary and different parts of Europe simultaneously—Defeated by Corvinus, king of Hungary—Otranto captured by the Turks, and afterwards abandoned—Pope Sextus IV. implores the aid of Christian Europe against the Turks—Distracted state of Italy—Death of Mahomet II., and divisions in his family—Zizim disputes the Turkish empire with Bajazet, and visits Europe—Charles VIII. of Naples, engages in a crusade against the Turks—Alphonso II. of Arragon—Italy invaded, and Rome possessed by the French—Andrew Palæologus sells his claims to the empire of the East—Death of Zizim—-Bajazet declares war against Venice—Negotiates a treaty—Undertakes an expedition against Portugal—Commercial ambition