Question

What stopped the advance of the Ottoman Empire into Europe in 1529?

Answer 1

The Ottoman Empire's failure to effect a successful Siege at Vienna. 
Particularly, the Polish army under Jan III Sobieski routed the Ottoman Encampment at Vienna and forced the Ottoman Empire to retreat. Previously, the Austrian and Hungarian armies had themselves been routed by the Ottomans at the Battle of Mohacs.

Answer 2

The advance of the Ottoman Empire into Europe was stopped b the fact that they an unsuccessful siege in Vienna. Following on from this, their Encampment was also routed by Jan III Sobeski, of the Polish Army