[Defensor Fidei]

Originally Posted by Hrvoje

You didn't stop them, moreover Serbia and Serbian nobles were Turkish allies in all battles against European Christendom, and later was constituent part of Ottoman empire and served Turkish interests for centuries.

"...The Hungarian royal army, meanwhile, was moving towards the battle. Sigismund's force was engaged with the Ottoman cavalry, when it was ambushed by the Serbian allies of Sultan Bajazet, led by Stephen Lazarevitch, who had retained his lands at the price of becoming an Ottoman vassal. This attack by the Serbs broke the Hungarians, and when Sigismunds banner was cast down, the army dissolved. Sigismund himself managed to escape downstream to Constantinople, but the Sultan, apparently enraged by earlier massacres of Turkish prisoners, killed all but a dozen of his French captives. Very few survivors of the battle returned to the west..."

http://www.rickard.karoo.net/article...nicopolis.html