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.
Christianity in the 4th century
Disunion in the Roman Empire further contributed to disunion in the Church. Emperor Diocletian divided the administration of the eastern and western portions of the empire in the early 4th century, though subsequent leaders (including Constantine) aspired to and sometimes gained control of both regions. Theodosius I, who established Christianity as the official religion of the Roman Empire, died in 395 and was the last emperor to rule over a united Roman Empire; following his death, the division into western and eastern halves, each under its own emperor, became permanent. By the end of the 5th century, the Western Roman Empire had been overrun by the Germanic tribes, while the Eastern Roman Empire (known also as the Byzantine Empire) continued to thrive. Thus, the political unity of the Roman Empire was the first to fall.