337 A.D., Nicomedia – today İzmit, Turkey; Flavius Valerius Aurelius Constantinus Augustus, otherwise known as Constantine the Great, the first ‘official’ Christian Emperor of Rome, converting at age 40 (although only being baptized on his deathbed), dies at age 65. He ordered the first ecumenical council at Nicea – today İznik , Turkey, in 325 due to a controversy over the relationship of Christ the Son and God the Father resulting in the Nicean Creed.
1176 Aleppo, Syria; Hashshashins fail in their attempt to assassinate Ṣalāḥ ad-Dīn Yūsuf ibn Ayyūb, more well known in the west as Saladin. More’s the pity, as by his military aptitude the moslem forces under his command were able to conquer the army of the Kingdom of Jerusalem and later force the city’s surrender.
And lest we forget the folks in our southern hemisphere:
1858 Bogotá Columbia; Confederación Granadina (now the separate nations of Panama, Colombia & parts of Brazil) is formed by the congress of the Republic of New Granada passing a change in the constitution of that time.