Agrippina the Younger outraged by Claudius' adoption of Nero and his choice of Nero as successor, instead of choosing his own son Britannicus. Nero and Octavia were married on June 9, 53. Claudius later repented of marrying Agrippina and adopting Nero, began to favor Britannicus, and started preparing him for the throne. His actions allegedly gave Agrippina a motive to eliminate Claudius. The ancient sources say she poisoned Claudius on October 13, 54 with a plate of deadly mushrooms at a banquet, thus enabling Nero to quickly take the throne as emperor. Accounts vary wildly with regard to this private incident and according
Roman emperor to style themselves as Emperor of the Romans (later βασιλεύς Ῥωμαίων in Greek), but are often referred to in modern scholarship as Byzantine emperors. Constantine XI Palaiologos was the last Roman emperor in Constantinople, dying in the Fall of Constantinople to the Ottomans in 1453. The "Byzantine" emperors from Heraclius in 629 and onwards adopted the title of "basileus" (), which had originally meant "king" in Greek but became a title reserved solely for the Roman emperor and the ruler of the Sasanian Empire. Other kings were then referred to as "rēgas". In addition to their pontifical office, some emperors