The battle of Nicopolis, 1396

Shakib Arslan, in the section "The Turkish conquest of Constantinople", says that Bayazid I was besieging Constantinople in 1396 CE. He learned that an army led by Sigismund, king of Hungary, had come to its relief, and he met it at Nicopolis in the land of the Bulgarians. ¹

Arslan says that the battle took place on 25 September of that year, and that the Christian army was routed and largely destroyed, killed or captured. He notes that some French histories mention two battles, one of them in 1393 CE. ¹

This is an account of what Arslan alone says, and it has not been verified in the standard history books. It needs an additional source.