Origins & Early Life

Pope Gregory XIII (Latin: Gregorius XIII, Italian: Gregorio XIII, born Ugo Boncompagni; 7 January 1502 – 10 April 1585) was head of the Catholic Church and ruler of the Papal States from 13 May 1572 to his death in April 1585. He is best known for commissioning and being the namesake for the Gregorian calendar, which remains the internationally accepted civil calendar to this day. Ugo Boncompagni was born the son of Cristoforo Boncompagni (10 July 1470 – 1546) and Angela Marescalchi, and paternal grandson of Giacomo Boncompagni and Camilla Piattesi, in Bologna, where he studied law and graduated in 1530. He later taught jurisprudence for some years, and his students included notable figures such as Cardinals Alexander Farnese, Reginald Pole and Charles Borromeo.

Pivotal Works & Achievements

He had an illegitimate son after an affair with Maddalena Fulchini, Giacomo Boncompagni, but before he took holy orders, making him the last Pope to have left issue. At the age of 36, he was summoned to Rome by Pope Paul III (1534–1549), under whom he held successive appointments as first judge of the capital, abbreviator, and vice-chancellor of the Campagna e Marittima...

Enduring Legacy & Impact

The historical impact and works continue to influence the modern world.

Contemporary Figures & Related Historical Timelines

• Ahuitzotl — Contemporary (Died in 1502) (1502): Eighth Aztec ruler and Huey Tlatoani of Tenochtitlan, key to Aztec expansion.
• Andreas Palaiologos — Contemporary (Died in 1502) (1502): Eldest son of Thomas Palaiologos, claimant to the Byzantine imperial throne.
• Gonzalo Pizarro — Contemporary (Born in 1502) (1502): Spanish conquistador, brother of Francisco Pizarro, key figure in the conquest of the Inca Empire.
• Cardinal Richelieu — Contemporary (Born in 1585) (1585): Powerful French statesman who centralized royal authority and checked Habsburg power.
• Cornelius Jansen — Contemporary (Born in 1585) (1585): Influential Dutch Bishop and founder of the theological movement known as Jansenism.
• Heinrich Schütz — Contemporary (Born in 1585) (1585): Pioneering German early Baroque composer, bridging Italian style to Lutheran tradition.
• Abdul Basit 'Abd us-Samad — Shared historical date (01-01 · Born) (1927): Renowned Egyptian Quran reciter, celebrated for his melodious and emotionally engaging style.
• Arcadius — Shared historical date (01-01 · Born) (377): Eastern Roman Emperor who ruled from 395 to 408 AD, succeeding Theodosius I.
• Ali Sayad Shirazi — Shared historical date (04-10 · Died) (1999): Key Iranian military commander during the Iran–Iraq War, assassinated in 1999.
• Aliko Dangote — Shared historical date (04-10 · Born) (1957): Nigerian billionaire founder of Dangote Group, a major industrial conglomerate.
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