Emperor
The first Austrian Emperor was the last Holy Roman Emperor Francis II. In the face of aggressions by Napoleon, Francis feared for the future of the Holy Roman Empire. He wished to maintain his and his family's Imperial status in the event that the Holy Roman Empire should be dissolved, as it indeed was in 1806 when an Austrian-led army suffered a humiliating defeat at the Battle of Austerlitz. After which, the victorious Napoleon proceeded to dismantle the old "Reich" by severing a good portion from the empire and turning it into a separate Confederation of the Rhine. With the size of his imperial realm significantly reduced, Francis II, "Holy Roman Emperor" became Francis I, "Emperor of Austria". The new imperial title may have sounded less prestigious than the old one, but Francis' dynasty continued to rule from Austria and a Habsburg monarch was still an emperor ("Kaiser"), and not just merely a king ("König"), in name.
Ostrogothic Ravenna
In 476 the last emperor of the Western Roman Empire, Romulus Augustus, was forced to abdicate under invasions by Goths led by Odovacar. Upon the sacking of Rome by these Goths, Odovacar declared himself King of Italy and was able to conquer the peninsula as well as much of the "Dalmatian coast". Odovacar drew the ire of the imperial court at Constantinople as "a barbarian, a non-Roman, had deposed the Roman emperor in the original heartland of the empire. He had taken on the hated royal title and was getting ready to rule in the emperor’s place..." Odovacar, however, issued his coinage in the name of the emperor Nepos, whom Constantinople had never removed its recognition of when Romulus had assumed the imperial title therefore painting himself as merely overthrowing a previous usurper to the imperial throne.