# Nicaea 325 AD: Birth of Christian Orthodoxy (+ 13 more historical events on this day!) Page: https://stenobird.com/podcast/a-daily-dose-of-history-events-on-this-day-in-history-6397743/nicaea-325-ad-birth-of-christian-orthodoxy-13-more-historical-events-on-this-day Text version: https://stenobird.com/podcast/a-daily-dose-of-history-events-on-this-day-in-history-6397743/nicaea-325-ad-birth-of-christian-orthodoxy-13-more-historical-events-on-this-day.md Podcast: [A Daily Dose of History: Events on this Day in History](https://stenobird.com/podcast/a-daily-dose-of-history-events-on-this-day-in-history-6397743) Published: 2026-05-20T06:00:57+00:00 Episode link: https://chrt.fm/track/B8G9CB/traffic.megaphone.fm/KLSP5452840861.mp3 Audio file: https://chrt.fm/track/B8G9CB/traffic.megaphone.fm/KLSP5452840861.mp3 Processing state: not_requested JSON: https://stenobird.com/v1/public/podcasts/a-daily-dose-of-history-events-on-this-day-in-history-6397743/episodes/nicaea-325-ad-birth-of-christian-orthodoxy-13-more-historical-events-on-this-day Duration seconds: 595 ## Resource A Daily Dose of History (20 May 2026) Today's historical events: The First Council of Nicaea is formally opened, starting the first ecumenical council of the Christian Church. Empress Ariadne marries Anastasius I. The widowed Augusta is able to choose her successor for the Byzantine throne, after Zeno (late emperor) dies of dysentery. The Battle of Dun Nechtain is fought between a Pictish army under King Bridei III and the invading Northumbrians under King Ecgfrith, who are decisively defeated. While visiting the royal Mercian court at Sutton Walls with a view to marrying princess Ælfthryth, King Æthelberht II of East Anglia is taken captive and beheaded. The Second Battle of Lincoln is fought near Lincoln, England, resulting in the defeat of Prince Louis of France by William Marshal, 1st Earl of Pembroke. King Sancho IV of Castile creates the Estudio de Escuelas de Generales in Alcalá de Henares. The Battle of Alfarrobeira is fought, establishing the House of Braganza as a principal royal family of Portugal. John Cabot sets sail from Bristol, England, on his ship Matthew looking for a route to the west (other documents give a May 2 date). Portuguese explorer Vasco da Gama discovers the sea route to India when he arrives at Kozhikode (previously known as Calicut), India. Hernando Cortes defeats Panfilo de Narvaez, sent by Spain to punish him for insubordination. Ignatius of Loyola is seriously wounded in the Battle of Pampeluna. Cartographer Abraham Ortelius issues Theatrum Orbis Terrarum, the first modern atlas. Shakespeare's sonnets are first published in London, perhaps illicitly, by the publisher Thomas Thorpe. The city of Magdeburg in Germany is seized by forces of the Holy Roman Empire and most of its inhabitants massacred, in one of the bloodiest incidents of th… ## Actions - request_transcript: `POST https://stenobird.com/v1/public/podcasts/a-daily-dose-of-history-events-on-this-day-in-history-6397743/episodes/nicaea-325-ad-birth-of-christian-orthodoxy-13-more-historical-events-on-this-day/transcription-requests` — Idempotently request low-priority transcript generation for this episode. - read_markdown: `GET https://stenobird.com/podcast/a-daily-dose-of-history-events-on-this-day-in-history-6397743/nicaea-325-ad-birth-of-christian-orthodoxy-13-more-historical-events-on-this-day.md` — Read the agent-friendly Markdown representation of this episode resource. A page view does not enqueue transcription. Agents should invoke `request_transcript` explicitly when they need this episode processed. ## Transcript Full transcripts are not published on public pages unless there is a clear rights basis.