Namesakes for Ioannes

Bishops of Rome and the Popes: 23 popes, 2 antipopes
      John I (a.k.a. Ioannes)   523-526  
      John II (a.k.a. Ioannes)   533-535  
      John III (a.k.a. Ioannes)   561-574  
      John IV (a.k.a. Ioannes)   640-642  
      John V (a.k.a. Ioannes)   685-686  
      John VI (a.k.a. Ioannes)   701-705  
      John VII (a.k.a. Ioannes)   705-707  
      John VIII (a.k.a. Ioannes)   872-882  
      John IX (a.k.a. Ioannes)   898-900  
      John X (a.k.a. Ioannes)   914-928  
      John XI (a.k.a. Ioannes)   931-935  
      John XII (a.k.a. Ioannes)   955-964  
      John XIII (a.k.a. Ioannes)   965-972  
      John XIV (a.k.a. Ioannes)   983-984  
      John XV (a.k.a. Ioannes)   985-996  
      John (a.k.a. Ioannes)   997-998  
      John XVII (a.k.a. Ioannes)   1003  
      John XVIII (a.k.a. Ioannes)   1003-1009  
      John XIX (a.k.a. Ioannes)   1024-1032  
      John XXI (a.k.a. Ioannes)   1276-1277  
      John XXII (a.k.a. Ioannes)   1316-1334  
      John (a.k.a. Ioannes)   1410-1415  
      John XXIII (a.k.a. Ioannes)   1958-1963  
      John Paul I (a.k.a. Ioannes)   1978  
      John Paul II (a.k.a. Ioannes)   1978-2005  
Roman and Byzantine Emperors: 8 emperors
      Emperor Johannes Tzimisces (a.k.a. Ioannes)   969-976  
      Emperor Johannes Comnenus (a.k.a. Ioannes)   1118-1143  
      Emperor Johannes Ducas Vatatzes (a.k.a. Ioannes)   1221-1254  
      Emperor Johannes Ducas Lascaris (a.k.a. Ioannes)   1258-1261  
      Emperor Johannes Cantacuzenus (a.k.a. Ioannes)   1341-1354  
      Emperor Johannes Palaeologus; John V Palaeologus (a.k.a. Ioannes)   1341-1376; 1379-1390; 1390-1391  
      Emperor Johannes Palaeologus (a.k.a. Ioannes)   1390  
      Emperor Johannes Palaeologus (a.k.a. Ioannes)   1425-1448  
Saints: 3 saints
      Saint John Ducas Vatatzes (a.k.a. Ioannes)   1192-1254  
      Saint John XXIII (a.k.a. Ioannes)   1881-1963  
      Saint John Paul II (a.k.a. Ioannes)   1920-2005