All  

Roman emperor

Coronation of Louis the Pious as King of Aquitaine.

The Troubled Reign of Louis the Pious, Emperor of the Holy Roman Empire

Louis I (byname the Pious, the Fair, or the Debonair) was a King of the Franks and Holy Roman Emperor belonging to the Carolingian Dynasty. He lived between the 8 th and 9 th centuries AD and reigned...
Gaius Aurelius Valerius Diocletianus (ca.245-313), Roman Emperor Diocletian. Marble bust, XVIIth century, Florence, Italy. On display at Château de Vaux-le-Vicomte, France.

Emperor Diocletian: The Stabilizer of Rome Had a Green Thumb

Diocletian was a Roman emperor who lived between the 3rd and 4th centuries AD. Prior to his ascension to the throne, the Roman Empire was going through the Crisis of the Third Century, a period...
A 16th century fresco depicting the Council of Nicaea.

The Council of Nicaea: Pagan Emperor Constantine Used Christianity to Unify Church and State

The Council of Nicaea (also known as the First Council of Nicaea) was the first ecumenical council of the Christian Church. This council, which was convened in 325 AD, was assembled by the Roman...