シメオン1世
Around the same time, Tsar Simeon I of Bulgaria made overtures to John, offering the renounce his nation’s obedience to the Patriarch of Constantinople, and place his kingdom under the ecclesiastical authority of the popes at Rome. John sent two legates, who only made it as far as Constantinople, but whose letters urging Simeon to come to terms with the Byzantine Empire were delivered to him. However, John did confirm Simeon’s title of "Tsar" (emperor), and it was John’s representatives who crowned Simeon’s son Peter I of Bulgaria as Tsar in 927. Finally, John sent a legate to act as intermediary to attempt to stop a war between the Bulgarians and Croatians.