On this day in 1582: Pope Gregory XIII announces the new Gregorian calendar
Saint Dominic, Pope Gregory XIII and King Philip IV of Spain Venerating the Madonna of the Rosary Painting by Antoon van den Heuvel - Fine Art America
The time the pope made 10 days disappear
Pope Gregory XIII gave us the leap year – but his legacy goes so much further
The Dragon and the Calendar - Pope Gregory XIII
Book of Hours of Gregory XIII « Facsimile edition
Gregory XIII; Ugo Boncompagni (7 January 1502 to 10 April 1585) was Pope from 1572 to 1585; Historical; digitally restored reproduction from a 19th century original. - Album alb9818666
Pope Gregory XIII | Facts & Legacy | Study.com
Pope Gregory XIII, 1502 – 1585, born Ugo Boncompagni Stock Photo - Alamy
Gregory III and the Foreign Communities in Rome | Bibliotheca Hertziana – Max Planck Institute for Art History
Pope Gregory XIII - Wikipedia
Portrait of Pope Gregory XIII
GREGORY XIII (1502-1585). Pope (1572-1585). Engraving
Pope gregory xiii hi-res stock photography and images - Alamy
Portrait of Pope Gregory XIII (1502-1585) Pope of the Catholic Church. Dated 19th century Stock Photo - Alamy
Knights of the Altar - St Bartholomew Parish, Baao, CS - DID YOU KNOW: Pope Gregory XIII ordered to standardized the calendar because Julian calendar did not properly reflect the actual days
The Tomb of Pope Gregory XIII - Inside The Vatican Pilgrimages
EHS on X: "#OTD in history the Gregorian Calendar was introduced by Pope Gregory XIII... Did you know yesterday was the 4 October?!... back in 1582, that is. #churchhistory #religioushistory https://t.co/onqGvEoNux" /
Pope Gregory XIII - Wikipedia
Portrait of Pope Gregory XIII (1502 - 1585) - The Online Portrait Gallery
The Funerary Monument to Pope Gregory XIII in St Peter's Basilica in Rome - Walks in Rome (Est. 2001)
Gregory XIII | Catholic Answers Encyclopedia
Gregory XIII | Biography, Papacy, Gregorian Calendar, & Facts | Britannica
The Pope who established our modern calendar, and why we use it today - YouTube
