March 23, 332 (traditional date): Gregory the Illuminator, who converted a nation before Constantine even embraced Christianity, dies. A missionary to his homeland of Armenia, he converted King Tiridates, and much of the kingdom followed suit. Soon Christianity was established as the national religion, with Gregory as its bishop (see issue 57: Conversion of Rome).
March 23, 1540: Waltham Abbey in Essex becomes the last monastery in England to transfer its allegiance from the Catholic Church to the newly established Church of England.
March 23, 1743: George Friedrich Handel's oratorio "Messiah" plays in London and is attended by the king, who stood instantly at the opening notes of the Hallelujah Chorus—a tradition ever since (though some historians have suggested it was because he was partially deaf and mistook it for the national anthem). The oratorio was actually quite controversial, since it used the words of God in the theater, and the title only made things worse. Handel compromised a bit by dropping the "blasphemous" title from handbills. It was instead called "A New Sacred Oratorio.
March 23, 1966: The Archbishop of Canterbury meets at the Vatican with Pope Paul VI—the first such meeting between Anglican and Catholic leaders since Henry VIII broke with Rome more than 400 years before.