The Holy Roman Empire of the German nation is most commonly referred to as simply the German Empire.
Many historians state that Charles the Great, more commonly known as Charlemagne founded the Holy Roman Empire. However actually Charlemagne founded the Carolingian Empire, the Holy Roman Empire was formally established by Otto I. Charles was King of the Franks and expanded his empire to conquer France, Benelux, Germany, North Italy, Northeastern Spain and Greater Moravia, forming a nearly unified Europe for the first time in history. He was crowned as Emperor of the Romans by the Pope, which angered Eastern Roman Empress Irene, as she also held the title of Empress of the Romans. Charlemagne died in 814 and the Carolingian Empire was split between his sons Charles, Pepin and Louis.
The empire of Charlemagne now consisted of the Easter Empire, the Central Empire and Western Empire. The Western Empire eventually formed into France and the Eastern and Central Empires formed the Holy Roman Empire. Europe was once again divided into many states.
Establishment of the Holy Roman Empire
Otto I was Duke of Saxony and began unifying the Kingdom of Germany, ruling with an iron fist. Defending Germany from the Hungarian invasions, he was deemed as the savior of Christian Europe. He also conquered the Kingdom of Italy and he was coronated by the Pope as Holy Roman Emperor. Otto I died in 962, his son Otto II succeeded him.
Over the course of many centuries the empire had its ups and downs. The Pope criticized the Emperor and this led to the investiture controversy over who could appoint bishops. One of the last greatest emperors was Frederick I Barbarossa who was a strong king and solidified his empire. He died while leading a crusade, initiating a period of decline of the empire. Eventually it lost Northern Italy and parts of Greater Moravia, mostly just consisting of Germany.
Revival and Centralization
Mary of Burgundy
Mary of Burgundy was the Duchess of Burgundy, one of the most powerful states in medieval Europe. She married Maximilian I who was the only son of Emperor Frederick III, Holy Roman Emperor. Unlike in real life, she was ambitious and independent and was a very good leader. She managed to defend her empire from France and she did not die by falling off a horse, instead Maximilian did. She expanded her territory into the Netherlands and Germany and reinstalled the capital in Bruges, which had become the largest city in all of Europe. When the emperor Frederick III died her son, Philip I became Holy Roman Emperor. But she was de facto empress regent and eventually forced him to abdicate and instead took the throne herself as the first Holy Roman Empress. She received many complains from all of Europe, especially from the Pope, who did crown her Empress, but with reluctance. Under her more than thirty years reign she centralized and expanded the Roman Empire to cover all of Germany, Benelux, Northern Italy, West Poland, parts of France, Burgundy, Greater Moravia and Hungary. She died in 1525 and was succeeded by her grandson, Charles, later known as Charles V.
Mary's grandson, Charles would continue her centralization efforts. And expanded the empire even further, into Southern Italy and into the Roman Empire. He was also King of Spain and ruled half of Europe. However this was apparently tedious to him, which led to his eventual retirement in 1556. The Holy Roman Empire descended in an irreversible period of decline.
Decline and Modern Period
The Holy Roman Empire lost the Benelux, North Italy, Hungary and parts of Poland by 1600. The last short period of prosperity was when Maria Theresa became Holy Roman Empress, she managed to temporarily expand the empire, before it was permanently limited to Germany, Switzerland, Austria and Bohemia. Most crucial during this time were the "Imperial Reforms" of Francis I, which, unilaterally, solidified the power of the emperor, turning the empire into an absolute monarchy, and united the entire empire as one, singular state under an autocratic emperor. The Holy German Empire was one of the main forces of the Great War, where it allied itself with the Roman Empire and other nations. Under Frederick V, Germany conquered France, the Netherlands, Poland and Denmark. While defeated, Tambapanni stubbornness during negotiations meant that no territory changed hands in the war's resolution. War costs did destroy the economy. However, the empire quickly recovered and was named a "miracle" for its rapid economic growth. Today the empire is the second largest European economy with a GDP of more than 3,850,000 million US dollars. It is an important member of the European Union and still exercises some influence over the world.