Stefan Lazarević participated as an Ottoman vassal in the Battle of Karanovasa in 1394, the Battle of Rovine in 1395, the Battle of Nicopolis in 1396, and in the Battle of Angora in 1402. After Angora, he visited Constantinople, the capital city of the Byzantine Empire, where he was given the title of Despot, and since then his state became known as the Serbian Despotate in 1402.[15][16]