It was one of the first class battles of all time, not merely due to the outcome.
http://en.wikipedia.org/wiki/Battle_of_Vienna
The battle started before all units were fully deployed. Early in the morning, at 4h, the Ottomans attacked, seeking to interfere with the deployment of the Holy League troops. Charles of Lorraine moved forward with the Imperial army on the left and the other Holy Roman Empire forces in the center.
Mustafa Pasha launched a counter-attack with most of his force, but held back some of the elite Janissary and Sipahi units for a simultaneous assault on the city. The Ottoman commanders had intended to take Vienna before Sobieski arrived, but time ran out. Their sappers had prepared another large and final detonation under the Löbelbastei, to breach the walls. While the Ottomans hastily finished their work and sealed the tunnel to make the explosion more effective, the Viennese “moles” detected the tunnel in the afternoon. One of them entered and defused the load just in time.
At that time, above the “subterranean battlefield”, a large battle was going on, as the Polish infantry launched a massive assault upon the Ottoman right flank. Instead of focusing on the battle with the relief army, the Ottomans continued their efforts to force their way into the city.
There was a moment during the battle where Kara Mustafa personally ordered the execution of 30,000 Christian hostages.
After twelve hours of fighting, the Poles held the high ground on the right. On the flanks, it is recorded that out of the forest the Polish cavalry slowly emerged and received a cheer from the onlooking infantry who had been anticipating their arrival. The Holy League cavalry waited on the hills, and watched the infantry battle for the whole day. At about 17h, the Polish King ordered the cavalry attack in four groups, one of the Holy Roman Empire and three Polish. Twenty thousand horsemen charged down the hills (the largest cavalry charge in history). Jan III Sobieski led the charge at the head of 3,000 Polish heavy lancers, the famed “Winged Hussars”. The Lipka Tatars who fought on the Polish side wore a sprig of straw in their helmets to distinguish themselves from the Tatars fighting on the Ottoman side. The charge broke the lines of the Ottomans, who were tired from the long fight on two sides. In the confusion, the cavalry headed straight for the Ottoman camps, while the remaining Vienna garrison sallied out of its defenses and joined in the assault.
The Ottoman troops were tired and dispirited following the failure of both the sapping attempt and the brute force assault on the city. The arrival of the cavalry turned the tide of battle against them, sending them into retreat to the south and east. In less than three hours after the cavalry attack, the Christian forces had won the battle and saved Vienna.
After the battle, Sobieski paraphrased Julius Caesar’s famous quote (Veni, vidi, vici) by saying “Venimus, Vidimus, Deus vincit” – “We came, We saw, God conquered”.
https://www.facebook.com/pages/Battle-of-Vienna/102289036491517
Nice. Thanks, Civ, I always learn from you.