The fact of “empire” does not always sit well with the legality of “emperor”. It’s tricky with neighbours, who may not like you telling them you are king of kings. And it’s tricky with locals, who may not like being reminded that your power is total.
16 January is a day to look at emperors who were chary about the word “emperor” and a day to look at kingdoms which have gone to history as empires.
So to Rome. The measure of supreme power – imperium – and who held it – imperator – were dangerous topics both in republican and in imperial Rome. The Senate’s grant of the title “Augustus” to Octavian is the key date marking empire over republic. This took place on 16 January 27 BCE. Loosely, the ruler of the empire was thereafter likely to have Caesar, Augustus and Imperator in the bag of names and titles but was likely to remind others of their rule – and to be reminded by those others – by use of the first two only.
So to Britain and Spain. Neither empire has ever had an emperor and only one person has been king of both. In 1554 Philip a son of a Holy Roman Emperor married England’s Queen Mary. Look closely at the English shilling below. You will see HISP, Spain, and ANG, England. The coin came online after 16 January 1556, the day this king of England became also king of Spain.
Over 200 years later, on 16 January 1794, Edward Gibbon died. An Englishman, his claim to fame was his monumental The History of the Decline and Fall of the Roman Empire.