The main source of the events surrounding the battle is the Bazm u Razm, written by Aziz ibn Ardashir Astardbhdi, one of Burhan al-Din's courtiers.[8] Manuel II's letters provide additional information, particularly pertaining to the chronology of the campaign;[10] traditionally, historiography placed the campaign in 1392, but Manuel did not participate in a campaign in 1392, and the historian Elisabeth Zachariadou has shown that Bayezid was likely campaigning in the northwestern Balkans in that year (see below).[11]