How was Vienna defended during the Ottoman siege of 1683?

During the 1683 siege of Vienna, the city's defense relied on a combination of internal resistance and the arrival of external relief forces. As 150,000 Ottoman troops under the grand vizier Kara Mustafa surrounded the city, they captured the outer fortifications and began tunneling beneath the inner walls.12

While imperial troops under Charles of Lorraine initially attempted to hold back the invaders, they were forced to retreat, leaving the city to endure the siege from July 17 to September 12. The defense was ultimately secured by a massive relief army of 80,000 troops, which included forces from Saxony, Bavaria, and various German principalities.12

On September 12, this combined force, led by King John III Sobieski of Poland, launched a decisive attack from the Vienna hills. After 15 hours of intense fighting, the relief army drove the Ottoman forces from their trenches, effectively ending the siege and marking a turning point in Ottoman domination in eastern Europe.12