The Two Sieges of Vienna by the Ottoman Turks

The fall of Constantinople in 1453 was followed by a rapid extension of the arms and power of the conqueror, Mahomet II. Within a short period he subjected Persia, the whole of Greece and the Morea, most of the islands of the Archipelago, and Trebisond on the coast of Asia Minor, the seat of the Greek empire of the Comnenes. The last of that dynasty, Daniel Comnenus, he took prisoner, and shortly after caused him with his family to be executed for the alleged offence, probably a mere pretext, of an understanding with the Persians. In 1467 Mahomet took from the Venetians, in addition to several possessions in the Morea, the island of Euboea, and, in 1474, Caffa from the Genoese. The hostilities in which he was soon afterwards involved with Persia hindered him from further pursuing his conquests against the Christian powers, who on their side were prevented by their unhappy dissensions and divisions from attempting to retrieve their losses. In general their campaigns against the Turks were confined to purely defensive operations, and it was not till a much later period that common need and danger produced a more general system of aggressive action...