May 10 (Eastern Orthodox liturgics)

• Saint Simon the Zealot, Apostle (1st century)^[1]
• Martyr Hesychius the Palatine of Antioch (c. 304)^[2]
• Saint Isidora the Fool-for-Christ, of Tabennisi, Egypt (c. 365)^[3]
• Saint Isidore of Alexandria (Isidore The Simple-Minded) (319-404), Hieromonk and Hospitaller (hospital administrator) (404)^{[4][note 2]}
• Venerable Passarion the Presbyter (Passarion of Palestine), Agapius and Philemon (mid-5th century)^{[7][note 3]}
• Blessed Thais (Taisia) of Egypt (5th century)^[3]
• Saint Laurence of Egypt, monk (6th century)^[3]

• Martyrs Calepodius, Palmatius, Simplicius, Felix, Blanda and Companions (c. 222–232)^[11][12]
• Martyrs Alphius, Philadelphus, Cyprian, at Lentini in Sicily (251)^[11][12][13]
• Martyrs Erasmus, Onesimus, and 14 other martyrs, in Sicily (251)^[14]
• Saint Aurelian of Limoges, Disciple of St Martial of Limoges in France (3rd century)^[12]
• Martyrs Quartus and Quintus, two citizens of Capua who were condemned and executed in Rome.^[11][12]
• Saint Conleth, first Bishop of Kildare (c. 519)^[15] (see also: May 3 and May 4)^[16][17][18]
• Saint Comgall, founder and abbot of Bangor (602)^[12][19]
• Saint Cataldus, born in Munster in Ireland, became a monk at Lismore, then Bishop of Taranto; renowned for miracles (7th century)^[11][12]
• Virgin-martyr Solangia (Solange) (880)^[12]

• Saint Simon of Vladimir and Suzdal (Kiev Caves), Bishop (1226)^[20]
• Venerable Laurence, monastic founder at Mt. Pelion in Volos (late 14th century)^[21]
• Blessed Simon of Yurievets and Zharki, Fool-for-Christ (1584)^[3]
• Saint Eustathios of Crimea (1745-1759), martyred in Theodosia, Crimea (1759)^[22]
• Saint Synesius of Irkutsk (1787)^{[3][note 4]}
• Saint Yoakim Krchovski (1820)^[24][25]

• The passage of the relics (1087) of St. Nicholas the Wonderworker through the island of Zakynthos, while on their way to Bari.^[26]
• Translation of the relics (1670) of the blessed martyr Basil of Mangazea in Siberia (1602)^[3][27]
• "Kiev-Bratskaya" Icon of the Mother of God (1654)^{[28][note 5]}
• Repose of Eldress Taisia (Thaisia) of Voronezh (1840)^[3]
• Repose of Hieromonk Andrew (Abramius in Schema) of Whitehoof Convent (1902)^[3]
• Slaying of Soldier Eugene Rodionov in Chechnya (May 23, 1996)^[30]

• 
  Icon of St. Simon the Zealot.
• 
  Chapel of St. Aurelian, Limoges.
• 
  St. Comgall's parish church, Bangor.
• 
  St. Cataldus.
• 
  Church of St. Solange, Sainte-Solange, Cher, France.

• May 10/23. Orthodox Calendar (PRAVOSLAVIE.RU).
• May 23 / May 10. HOLY TRINITY RUSSIAN ORTHODOX CHURCH (A parish of the Patriarchate of Moscow).
• Complete List of Saints. Protection of the Mother of God Church (POMOG).
• Dr. Alexander Roman. May. Calendar of Ukrainian Orthodox Saints (Ukrainian Orthodoxy - Українське Православ'я).
• May 10. Latin Saints of the Orthodox Patriarchate of Rome.
• May 10. The Roman Martyrology.

Greek Sources

• Great Synaxaristes: (in Greek) 10 ΜΑΪΟΥ. ΜΕΓΑΣ ΣΥΝΑΞΑΡΙΣΤΗΣ.
• (in Greek) Συναξαριστής. 10 Μαΐου. ECCLESIA.GR. (H ΕΚΚΛΗΣΙΑ ΤΗΣ ΕΛΛΑΔΟΣ).

Russian Sources

• (in Russian) 23 мая (10 мая). Православная Энциклопедия под редакцией Патриарха Московского и всея Руси Кирилла (электронная версия). (Orthodox Encyclopedia - Pravenc.ru).
• (in Russian) 10 мая (ст.ст.) 23 мая 2013 (нов. ст.). Русская Православная Церковь Отдел внешних церковных связей. (DECR).