This is a list of the top-level leaders for religious groups with at least 50,000 adherents, and that led anytime from January 1, 801, to December 31, 900. It should likewise only name leaders listed on other articles and lists.
Church of Rome (complete list) –
Leo III, Pope (795–816)
Stephen IV, Pope (816–817)
Paschal I, Pope (817–824)
Eugene II, Pope (824–827)
Valentine, Pope (827)
Gregory IV, Pope (827–844)
Sergius II, Pope (844–847)
Leo IV, Pope (847–855)
Benedict III, Pope (855–858)
Nicholas I, Pope (858–867)
Adrian II, Pope (867–872)
John VIII, Pope (872–882)
Marinus I, Pope (882–884)
Adrian III, Pope (884–885)
Stephen V, Pope (885–891)
Formosus, Pope (891–896)
Boniface VI, Pope (896)
Stephen VI, Pope (896–897)
Romanus, Pope (897)
Theodore II, Pope (897)
John IX, Pope (898–900)
Benedict IV, Pope (900–903)
Church of Constantinople (complete list) –
Tarasius, Patriarch of Constantinople (784–806)
Nikephoros I, Patriarch of Constantinople (806–815)
Theodotus I Kassiteras, Patriarch of Constantinople (815–821)
Antony I, Patriarch of Constantinople (821–836)
John VII Grammaticus, Patriarch of Constantinople (836–843)
Methodius I, Patriarch of Constantinople (843–847)
Ignatius I, Patriarch of Constantinople (847–858, 867–877)
Photius I the Great, Patriarch of Constantinople (858–867, 877–886)
Ignatius I, Patriarch of Constantinople (847–858, 867–877)
Photius I the Great, Patriarch of Constantinople (858–867, 877–886)
Stephen I, Patriarch of Constantinople (886–893)
Antony II Kauleas, Patriarch of Constantinople (893–901)
List of 9th-century religious leaders Wikipedia (Text) CC BY-SA