Next? Orthodox Christians have been on the front line against Islam since the jihad boiled out of Arabia in the 7th century. Westerners like to remember Charles Martel, the heroes of the Reconquista, the Holy League that triumphed at Lepanto, and Jan Sobeiski riding to the relief of Vienna but were it not for the centuries of resistance to the advance of Islam by the Orthodox Christian Roman Empire in countless engagements, by the Serbs, including the sacrifice of the army under St. Lazar the Tsar-Martyr on the field of Kosovo, and the resistance of Vlad Tepes even after the Fall of Constantinople, Vienna could have been in Muslim hands in the 10th century.