|Co-emperor of the Byzantine Empire|
Nikephoros Diogenes (Greek: Νικηφόρος Διογένης), Latinized as Nicephorus Diogenes, was the son of Byzantine Emperor Romanos IV Diogenes and Eudokia Makrembolitissa. Crowned co-emperor during his father's reign, he later served as a general during the reign of Emperor Alexios I Komnenos, scoring successes in the Byzantine campaigns against the Normans and Pechenegs, as well as governor of Crete.
Nikephoros's father, Romanos IV Diogenes, died when he was still a boy. Although elevated to the rank of co-emperor on his birth, he was banished to a monastery along with his mother after the fall of Romanos. Alexios I Komnenos took in Nikephoros and his brother Leo and treated them well.
While campaigning against barbarian forces led by Bolcanus, Nikephoros Diogenes planned to kill the Emperor and usurp the throne. He placed his tent very close to the Emperor's and at night hid his sword and entered the tent, intending to kill him. However, while the Emperor was sleeping a maid was awake fanning away mosquitoes. Seeing the maid, Nikephoros panicked and fled back to his tent. Later, he tried again at the house of Constantine Doukas Porphyrogennetos in the Serres region of Macedonia. This time however he was caught trying to enter the bathhouse with his sword.
Following his arrest he revealed that Empress Maria of Alania knew of the plot, but had insisted that Alexios not be killed but merely overthrown. It was also revealed that Diogenes had many co-conspirators. To kill or maim all of them would have been too dangerous for Alexios, who feared that his troops would mutiny if sent out that order. Instead he circulated the rumor that Diogenes had been blinded, so as to strike fear in his fellow-plotters. The plan worked, but the rumor grew so strong that Alexios' men were convinced that they were actually ordered to blind Nikephoros Diogenes. So without the permission of the Emperor, who was very fond of the man, Nikephoros Diogenes was blinded.
Nikephoros Diogenes lived out his life under protection of the Emperor and studied history and other sciences, getting his servants to read aloud to him.
- Canduci, pg. 272
- Holmes 2005, p. 222
- Anna Komnene translated by Elizabeth A. S. Dawes (2009). "Turkish War : Dalmatian Interlude (1092-4) : Conspiracy of Nicephorus Diogenes (1094)". Fordham University. Retrieved October 29, 2009.
- (Primary Source) Anna Komnene, The Alexiad
- Canduci, Alexander (2010), Triumph & Tragedy: The Rise and Fall of Rome's Immortal Emperors, Pier 9, ISBN 978-1-74196-598-8
- Holmes, Catherine (2005). Basil II and the governance of Empire (976-1025) (2005 ed.). Oxford University Press. ISBN 0-19-927968-3.
- Skoulatos, Basile (1980), Les personnages byzantins de I'Alexiade: Analyse prosopographique et synthese (in French), Louvain: Nauwelaerts