66 Emperor Nero creates the Legion I Italica.
69 Vespasian, formerly a general under Nero, enters Rome to claim the title of emperor.
221 Liu Bei, a Chinese warlord and member of the Han royal house, declares himself emperor of Shu-Han and claims his legitimate succession to the Han Dynasty.
364 Roman Emperor Valentinian I appoints his brother Flavius Valens co-emperor.
421 Constantius III becomes co-Emperor of the Western Roman Empire.
455 Roman military commander Avitus is proclaimed Emperor of the Western Roman Empire.
668 Eastern Roman Emperor Constans II is assassinated in his bath at Syracuse, Italy.
893 Simeon I of Bulgaria is crowned Emperor of the first Bulgarian empire
1203 Isaac II Angelus, restored Eastern Roman Emperor, declares his son Alexius IV Angelus co-emperor after pressure from the forces of the Fourth Crusade.
1204 Baldwin IX, Count of Flanders is crowned as the first Emperor of the Latin Empire.
1619 Ferdinand II is elected emperor of the Holy Roman Empire.
1806 Former leader of the Haitian Revolution, Emperor Jacques I of Haiti is assassinated after an oppressive rule.
1814 Emperor Napoleon I of France arrives at Portoferraio on the island of Elba to begin his exile.
1822 Emperor Agustín de Iturbide attempts to dissolve the Mexican Empire.
1864 Emperor Maximilian of Mexico arrives in Mexico for the first time.
1867 The Austro-Hungarian agreement known as Ausgleich ("the Compromise") is born through Act 12, which establishes the Austro-Hungarian Empire; on June 8 Emperor Franz Joseph is crowned King of Hungary.
1870 Emperor Napoleon III of France is deposed and the Third Republic is declared.
1889 Menelek of Shoa obtains the allegiance of a large majority of the Ethiopian nobility, paving the way for him to be crowned emperor.
1908 Child Emperor Pu Yi ascends the Chinese throne at the age of two
1931 Emperor Haile Selassie of Ethiopia signs the first constitution of Ethiopia.
1941 Emperor Haile Selassie returns to Addis Ababa, Ethiopia; the country commemorates the date as Liberation Day or Patriots' Victory Day.
1974 Emperor Haile Selassie of Ethiopia, 'Messiah' of the Rastafari movement, is deposed following a military coup by the Derg, ending a reign of 58 years.
1979 A coup d'état in the Central African Empire overthrows Emperor Bokasa I.