German Empire
The high command under Paul von Hindenburg and Erich Ludendorff increasingly controlled the country, but in October after the failed offensive in spring 1918, the German armies were in retreat, allies Austria-Hungary and the Ottoman Empire had collapsed, and Bulgaria had surrendered. The Empire collapsed in the November 1918 Revolution with the abdications of its monarchs. This left a postwar federal republic and a devastated and unsatisfied populace, which later led to the rise of Adolf Hitler and Nazism.
Roman Empire
The Roman Empire (, ; Koine and Medieval Greek: Βασιλεία τῶν Ῥωμαίων, tr. ) was the post-Roman Republic period of the ancient Roman civilization. It had a government headed by emperors and large territorial holdings around the Mediterranean Sea in Europe, North Africa, and West Asia. From the constitutional reforms of Augustus to the crisis of the third century, the Empire was a principate ruled from the city of Rome (27 BC - 285 AD). The Roman Empire was then divided between a Western Roman Empire, based in Milan and later Ravenna, and an Eastern Roman Empire, based in Nicomedia and later Constantinople, and it was ruled by multiple emperors (with the exception of the sole rule of Constantine between 324 and 337, and Theodosius between 392 and 395). The Western Empire collapsed when Ravenna fell to the Germanic Herulians of Odoacer in 476 AD. The end of the Western Roman Empire is traditionally used to mark the end of ancient Rome. The Eastern Empire, known in the post-Roman West as the Byzantine Empire, collapsed when Constantinople fell to the Ottoman Turks of Mehmed II in 1453.