One of the things I’ve always liked about alternate history is how, when it’s done well, it challenges you and forces you to really look at your assumptions. A good example is the Battle of Vienna in 1683. It’s often said in histories of the battle that the lifting of the siege of Vienna was a key moment in European history, halting the inexorable Ottoman conquest of the Continent.
This necessarily implies an alternate history (or a counterfactual, to use the more academic term): that if Vienna had fallen to the Ottomans, the Turkish empire would have swept onward, swallowing Germany and Italy and Poland, and maybe even France and Spain or Britain. When historians or the popular imagination label a historical event as significant, that label often carries such an implicit counterfactual: we’re saying that the event is important because a change in its outcome would have resulted in a very different subsequent history from the one we know.
This is especially easy to do with battles, as a battle can tip the course of events from one extreme to the other in a single afternoon. Our history books are full of places and dates that we’re sure are significant fulcra on which the world we live in balances: Tours 722, Hastings 1066, the destruction of the Spanish Armada 1588, Saratoga 1778, Trafalgar 1803, Waterloo 1815, Gettysburg 1863. Vienna 1683.
But do such assumptions always hold true? In the case of the siege of Vienna (and, most emphatically, the Battle of Waterloo), not really. The idea of endless hordes of Ottoman warriors spilling across the Alps isn’t a sustainable one.
Victorious in Arabia, North Africa and much of Slavic Europe, the Ottomans had already reached and passed the limit of empire they could successfully govern; the defeat at Vienna forced them to make a significant retreat and retrenchment over the next fifteen years. In that period they lost Hungary and Transylvania to Austrian occupation, the beginning of a slow whittling away of the Ottomans’ empire until its final dissolution in 1923.
A victory at Vienna would have marginally delayed this two-and-a-half-century decline rather than preventing it. Besides, the fall of Vienna and a Turkish invasion of the Germanies would have forced France to sit up and take notice of the Ottoman threat, much as the Confederate victory at First Bull Run galvanised the American North, alerting them that the South posed a more formidable opponent than they’d originally thought and steeling their resolve to win the conflict whatever the cost. France had a huge population advantage over the other European states in the seventeenth century and would have beat back an Ottoman invasion of Germany, so we’d be left with a French-dominated Central Europe–but France dominated Central Europe anyway until Napoleon abdicated the French throne in 1814.
Europe would have certainly looked different had the Turks taken Vienna, but the differences would have been far more subtle (and therefore probably far more interesting) than an Islamic conquest of the Continent. The idea that the German and Polish armies in 1683 saved Christendom simply doesn’t hold up.
Alternate history, of course, is looking at the world and asking, “What if?” But that’s a question we already ask, by the nature of historiography, when we study real history–only we often don’t realise that we’re asking it. Because of that, our answers can be careless, cursory and full of unsustainable assumptions. If we pause and ask “What if?” deliberately, then we can refine those answers and make them far better–which not only lead to some fascinating discussions, but also can end up altering our understanding of real history and the world it has created.