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.
Orestes (5th century general)
In 475, Orestes was appointed "magister militum" and "patricius" by Western Roman Emperor Julius Nepos. This proved to be a mistake on the part of Nepos. By August 28, 475, Orestes, at the head of the "foederati" levies, managed to take control of the government in Ravenna, which had been the de facto capital of the Western Roman Empire since 402. Julius Nepos fled without a fight to Dalmatia, where he would continue to reign until his assassination in 480. With the emperor far away, Orestes elevated his son Romulus to the rank of "Augustus", so that the last Western Roman emperor is known as Romulus Augustulus meaning "little Augustus" as the emperor was only a 15-year-old boy at the time he became emperor in 475.