"after the battle of Mohacs"
by cm

There were two battles of Mohács, but Dracula is talking about the first, a victory for the Ottomans.  

Mohács is a town in Hungary, and the Ottoman triumph there in 1526 led to the centuries-long partition of Hungary between the Habsburg Empire, the Ottoman Empire and Transylvania.  For Hungarians, the battle is still seen as a national disaster.

The second battle of Mohács, in 1687, saw the Holy Roman Empire force the Ottomans out of Hungary.