Order of the Iron Crown (Austria)
The Holy Roman Empire, ruled by the Habsburg dynasty, gave way to the Empire of Austria between 1804 and 1806. The last Holy Roman Emperor, Franz II, was proclaimed Emperor Franz I of Austria. His daughter, the Archduchess Maria Louise, was Napoleon’s second wife and Empress Consort, and the mother of Napoleon’s only legitimate son and heir, Napoleon, Duke of Reichstadt. With the collapse of Napoleon’s empire, Imperial Austria regained its traditional control of Lombardy as the Kingdom of Lombardy–Venetia.
Roman emperor
Due to the cultural rupture of the Turkish conquest, most western historians treat Constantine XI as the last meaningful claimant to the title Roman Emperor. From 1453, one of the titles used by the Ottoman Sultans was "Caesar of Rome" (Turkish: "Kayser-i Rum"), part of their titles until the Ottoman Empire ended in 1922. A Byzantine group of claimant Roman emperors existed in the Empire of Trebizond until its conquest by the Ottomans in 1461, though they had used a modified title since 1282.