The title King of the Romans (Latin: Rex Romanorum) — not to be confused with the early, partially mythical Kings of Rome — was carried by Holy Roman Emperors after they had been confirmed as Emperor, but before they had undergone the ceremony of coronation by the Pope.

The title had this function beginning late in the Salian period, but had already been used as early as Ottonian times onwards, especially by Emperor Henry II, when it began to supersede King of the Germans (Lat.: rex Teutonicorum), implying an imperial role that was, at that time, rejected by the papacy.

It was also the title of an heir-designate who was elected within the lifetime of the Emperor.

After coronation as Holy Roman Emperor (and sometimes even before that), the title was augmented with the imperial semper Augustus (ever augustus; "ever majestic" or "ever greater", Augustus deriving from the Latin verb augere, "to grow"). This connotation of "growth" implied an obligation to oppose the loss of royal prerogatives (as in Italy) or the loss of territory (as on the western border with France).

King of the Romans was also the name the Franks gave to Syagrius, a Roman general who ruled Northern Gaul in the late 5th century.

References

This article uses material translated from the corresponding article in the German-language wikipedia, which, in turn, cites a source that contains further references:

• H. Beumann: Rex Romanorum, in: Lexikon des Mittelalters (Dictionary of the Middle Ages, 9 vols., Munich-Zurich 1980-98), vol. 7, col. 777 f.