May 13 (Eastern Orthodox liturgics)

• Saint-Righteous Gamaliel the Elder, Pharisee, Teacher of The Law (mid 1th century)[1]
• Virgin-martyr Glyceria at Heraclea, Propontis (c. 138-161)[2][3]
• Martyr Laodicius, jailer of Saint Glyceria (c. 138-161)[4][5]
• Saint Theoctistus, monk from Tekoa, Palestine[6][note 2]
• Saint Pausicacus, Bishop of Synnada (606)[11]
• Saint Nicephoros, Presbyter of the monastery of Ephapsios[12][note 3]
• Saint Sergius (George) the Confessor of Constantinople, with his wife Irene and children (c. 829-842)[13][14]
• Saint Euthymius the New (the Illuminator) (1028),[15] founder of Iveron Monastery, and his fellow Georgian saints of Mount Athos:

• His father monk-martyr John of Iveron (998);[16] his cousin monk-martyr George of Iveron (1065);[17] and monk-martyr Gabriel of Iveron (10th century)[18][19]

• Saint Abban of Ireland, baptized in 165 AD, missionary in Abingdon, Oxfordshire (2nd century)[20]
• Martyr Alexander of Rome (284-305)[21][22]
• Saint Valerian of Auxerre, third Bishop of Auxerre in France, and defender of Orthodoxy against Arianism. (350)[23][24]
• Saint Onesimus of Gaul, fifth Bishop of Soissons in France (361)[24][25]
• Saint Servatius, Bishop of Tongres, defender against Arianism in the Netherlands (384)[3][24][26]
• Saint Agnes of Poitiers, chosen by St. Radegund to be Abbess of Holy Cross at Poitiers in France (588)[24]
• Saint Mael (Mahel), Ascetic on the Isle of Bardsey (6th century)[24]
• Saint Natalis (Natale), Bishop of Milan in Italy (751)[24]
• Saint Anno (Hanno, Annon), Bishop of Verona in Italy (780)[24]
• Saint Merwenna of Rumsey (Merwinna, Merewenna), first Abbess of Rumsey convent, in Hampshire (c. 970)[27][28][note 4]
• Blessed Fortis Gabrielli, Ascetic (1040)[24]

• Venerable monk-martyrs of Iveron Monastery, martyred by the Latins (c. 1259-1280)[29][30][31][note 5]
• Repose of Saint Macarius, Abbot of Glushitsa Monastery, Vologda (1480)[19][32][33][note 6]
• Righteous Virgin Glyceria of Novgorod (1522)[19][34]

• Consecration of the Monastery of Panagia Pantanassa (Most-Holy Queen of All), on the small island of Hagia Glykeria (Incirli Adasi) in the Bay of Tuzla (12th century)[37]
• Translation of the relics (1688) of Hieromartyr Saint Macarius, Archimandrite of Ovruch and Pinsk, from Kaniv to Pereyaslavl (1678)[19][33][38][note 7]
• Repose of righteous Priest Alexis of Bortsurmany, disciple of St. Seraphim of Sarov (1848)[39]
• Repose of Rassophore Monk John, of St. Nilus of Sora Monastery (1863)[19]
• Repose of Eldress Sepfora of Klykovo (1997)[19]

• 
  St. Glyceria.
• 
  St. Euthymius of Athos
• 
  St. George the Hagiorite.
• 
  St. Servatius, Bishop of Tongres.

• May 13. OCA - The Lives of the Saints.
• May 13/26. Orthodox Calendar (PRAVOSLAVIE.RU).
• May 26 / May 13. HOLY TRINITY RUSSIAN ORTHODOX CHURCH (A parish of the Patriarchate of Moscow).
• Complete List of Saints. Protection of the Mother of God Church (POMOG).
• May. Self-Ruled Antiochian Orthodox Christian Archdiocese of North America.
• Dr. Alexander Roman. May. Calendar of Ukrainian Orthodox Saints (Ukrainian Orthodoxy - Українське Православ'я).
• May 13. Latin Saints of the Orthodox Patriarchate of Rome.
• May 13. The Roman Martyrology.

Greek Sources

• Great Synaxaristes: (in Greek) 13 ΜΑΪΟΥ. ΜΕΓΑΣ ΣΥΝΑΞΑΡΙΣΤΗΣ.
• (in Greek) Συναξαριστής. 13 Μαΐου. ECCLESIA.GR. (H ΕΚΚΛΗΣΙΑ ΤΗΣ ΕΛΛΑΔΟΣ).

Russian Sources

• (in Russian) 26 мая (13 мая). Православная Энциклопедия под редакцией Патриарха Московского и всея Руси Кирилла (электронная версия). (Orthodox Encyclopedia - Pravenc.ru).
• (in Russian) 13 мая (ст.ст.) 26 мая 2013 (нов. ст.). Русская Православная Церковь Отдел внешних церковных связей. (DECR).