The Gates of Vienna

King of Poland-Lithuania and supreme commander of the Holy League relief army at the Battle of Vienna

You are Jan III Sobieski, King of Poland and Grand Duke of Lithuania, fifty-four years old, veteran of a dozen campaigns against Tatars, Cossacks, Turks, and Swedes, elected to the Polish throne by acclamation after your crushing victory over the Ottomans at Khotin ten years ago. You are the finest cavalry commander in Europe, and everyone in this army knows it. That is why the allied princes agreed to place you in supreme command despite the fact that you are technically not even a member of the Holy Roman Empire. You have marched your Poles south through heat, bad roads, and the Carpathian passes to reach this ridge overlooking Vienna. Below you, the Ottoman Empire's greatest army sprawls across the plain in a crescent of trenches, batteries, and tents. Vienna's walls are crumbling under two months of bombardment and mining. Signal rockets from Starhemberg's garrison arc into the sky at intervals, each one a plea for speed. You have perhaps seventy-two hours before the sappers finish their work and the city falls. Your army is tired from the march. Your allies are brave but poorly coordinated. The terrain between your position and the Ottoman camp is broken, wooded, and dangerous for the very cavalry that is your greatest weapon. But once your hussars reach open ground, nothing the Ottomans possess can stop a massed charge. You have written to your wife Marysienka: 'The Vizier has chosen poorly. He faces the city and shows us his back.' Now you must prove that observation correct before the mines go off.

Vienna has been under Ottoman siege since mid-July. Grand Vizier Kara Mustafa Pasha commands perhaps 150,000 men in a vast crescent of trenches, batteries, and mining tunnels that arc around the city's southern and western walls. Inside the city, Count Starhemberg's garrison of roughly 15,000 soldiers and armed citizens has held for two months, but the walls are crumbling. Ottoman sappers have driven mines beneath the Burg bastion and the Löbel bastion. A single successful detonation could open a breach that cannot be sealed. Emperor Leopold I fled to Passau weeks ago, leaving Starhemberg to hold or die. Now the relief has arrived. A coalition force of roughly 70,000 — Poles, Bavarians, Saxons, Franconians, Swabians, and Austrians under Duke Charles of Lorraine — has gathered on the north bank of the Danube and crossed into the Vienna Woods. You are King Jan III Sobieski of Poland-Lithuania, elected supreme commander of the relief army by agreement of the allied princes. Your 27,000 Poles include 3,000 winged hussars, the most feared heavy cavalry in Europe. The attack must come from the Kahlenberg heights down through wooded ridges toward the Ottoman camp spread across the plain. If you wait too long, the mines will breach Vienna's walls. If you attack piecemeal, the Ottoman numbers will swallow your columns in the broken terrain. Everything depends on coordination, timing, and the single massed cavalry charge that must shatter the Ottoman line before nightfall.