The first is the Roman Empire. Under the leadership of Caesar, Augustus and others, the powerful Roman Empire continued to expand to the outside world, reaching its peak in Trajan's period and controlling about 5.9 million square kilometers of territory. It starts from the two river basins in the east, reaches most of Britain in the west, reaches Egypt and North Africa in the south, and reaches Dasia north of the Rhine and Danube in the north. However, the failure of Teutonic Forest Campaign was the most painful failure in the most powerful era of ancient Rome. They were defeated by the barbarians. This battle prevented the large-scale expansion of powerful ancient Rome, and the Roman territory hardly increased.
The second period close to unification was the period of Frankish Empire. When Pippin's son Charlie was in office, he expanded greatly. In 800 AD, Charles was crowned emperor and became Charlemagne Empire. The Frankish Empire has advanced social system, powerful military force, rich country and vast territory. In fact, it has the ability to realize the unification of Europe. But in 843, according to the Verdun Peace Treaty, it was divided into three parts, namely, the West Frankish Kingdom, the Middle Frankish Kingdom and the East Frankish Kingdom. After the adjustment of the Treaty of molson in 870, it became the embryonic form of the French Kingdom, the Italian Kingdom and the First Reich of Germany. The three brothers divided the empire into three small countries, and Europe once again lost the opportunity of reunification.
The third possibility of reunification is the Napoleonic Empire. At that time, Napoleon established an empire with France as the core, including Prussia, Austria, Russia, Denmark and Sweden, and became the most powerful empire at that time. However, in 8 13, near Leipzig, Germany, Napoleon took180,000 people to fight with 300,000 allies from Russia, Prussia, Austria and other countries, and finally lost. Napoleon returned to the west bank of the Rhine and finally to Paris. The next year, the Senate announced the abolition of Napoleon's throne, and Europe once again lost the opportunity of reunification ~
The closest one was Hitler's conquest of Europe in World War II. 1942, the territory of Hitler's Third Reich almost covered the whole European continent, from the English Channel to the suburbs of Moscow, from North Africa to Norway, and almost the whole of Europe was shrouded in the shadow of Nazi terror. Finally, after the Battle of Stalingrad and the Battle of Kursk in 1943, the situation was finally saved, and Europe was not completely occupied ~