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.
Henry VII, Holy Roman Emperor
Henry VII (German: "Heinrich"; c. 1275 – 24 August 1313) was the King of Germany (or "Rex Romanorum") from 1308 and Holy Roman Emperor from 1312. He was the first emperor of the House of Luxembourg. 
During his brief career he reinvigorated the imperial cause in Italy, which was racked with the partisan struggles between the divided Guelf and Ghibelline factions, and inspired the praise of Dino Compagni and Dante Alighieri. He was the first emperor since the death of Frederick II in 1250, ending the great interregnum of the Holy Roman Empire; however, his premature death threatened to undo his life's work. His son, John of Bohemia, failed to be elected as his successor, and there was briefly another anti-king, Frederick the Fair contesting the rule of Louis IV.