To obtain an imperial crown from the Holy See, Kaloyan entered into correspondence with Pope Innocent III, offering to acknowledge papal primacy. His expansionist policy brought him into conflict with the Byzantine Empire, Serbia and Hungary. Emeric, King of Hungary allowed the papal legate who delivered a royal crown to Kaloyan to enter Bulgaria only at the Pope's demand. The legate crowned Kaloyan "King of the Bulgarians and Vlachs" on 8November 1204, but Kaloyan continued to regard his realm as an empire.