While the Arab caliphate never came close to extinguishing its Christian equivalent, its Mulim successor, the Ottoman Turkish empire, would do so twice. Sultan Mehmet's conquest of Constantinopel (renamed Istanbul) in 1453, thanks to superior artillery breaching its legendary walls, reduced the Byzantine empire to a shady mess and the Orthodox countries ripe for the picking. After their gradual conquest of the Balkans, the Ottomans even laid siege to Vienna, but ultimately the Catholic Hansburg empire was saved by a great coalition. In how far these religious wars constitute true jihad is as debatable as the Christian content of the crusades, as profane 'realpolitik' generally proved the decisive factor.
—KGF Vissers