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.
Kingdom of Arles
In 1365, Charles was the last emperor to be crowned King of Arles. In 1378, Charles appointed the Dauphin of France (later King Charles VI of France) as permanent Imperial vicar to administer nominally on behalf of the Empire what remained of Arelat, and from then on Arelat in effect ceased to exist. However, the title "King of Arles" remained one of the Holy Roman Emperor's subsidiary titles until the dissolution of the Empire in 1806, and the office of the Archbishop of Trier continued to act as an archchancellor and prince-elector for the King of the Romans (the designated future Holy Roman Emperor), a status that was confirmed by the Golden Bull of 1356.