Friedrich II (December 26, 1194-December 13, 1250), King of the Roman people of the Hohenstaufen Dynasty (reigned 1211 - 1250) and Holy Roman Emperor (crowned 1220). He was also King of Sicily (known as Frederick I from 1198 onwards), Holy Roman Emperor (reigned 1220-1250), King of Jerusalem (1225 - 1228), King of Italy and Lord of Burgundy.

You see, this is Christian loyalty!-- When Frederick II, who was participating in the Crusades, learned that German princes wanted to use the hands of Muslims to murder him, he said with emotion

We all hold equal scales and we don't want to treat them differently. We hope that the plaintiff or defendant, whether he is a Frankish or a Roman, will be tried under the same law-Frederick II on the Principles of Legislation

In order to carefully protect the purity of the god-given air, Zite ordered that no one should wash linen or hemp in rivers and lakes within 300 meters of the village to prevent the air from getting worse-Frederick II issued Europe's first environmental protection order

His grandfather Frederick I dyed his beard red with Italian blood, and his father Henry VI blew across Sicily like a raging north wind, leaving behind a mess. As the "third storm" of the Hohenstaufen Dynasty, he once again set off a great battle between the emperor and the Pope on the land of Europe. Finally, both sides suffered both losses, and also caused profound changes to the political pattern and system of Europe.

His father was King Henry VI of Germany, and his mother was Queen Constance of Sicily. When he was 3 years old, his father passed away and he followed his mother to Sicily to escape the war. His mother died a year later, and Pope Innocent III became the guardian of his noble orphan. He grew up in Sicily and has always loved Sicily since then. Sicily was a very special place at that time. It was located at the intersection of Western European Catholic civilization, Byzantine Orthodox Church and Arab Islamic civilization. It was invaded by the Normans of Northern Europe and was a crossroads of multiple civilizations. This diversified characteristic has a clear mark in Frederick's character and thought.

In that martial era, the political achievements of every famous emperor were accumulated by a series of battles, and Frederick was no exception. His martial arts can be divided into four parts: Sicily, Germany, North Italy and the Papal States, and Jerusalem.

In 1209, Frederick married Constance of Aragon, who brought a generous dowry, including a group of knights. Based on this, Frederick quickly defeated the conspiracy and rebellion of the Sicilian aristocrats and truly controlled the military and political power of Sicily. Later, Frederick vigorously weakened the power of the lords, aristocrats and the church in Sicily, strengthened the kingship, and built castles, seaports, navies, merchant ships, etc. In 1231, a new Sicilian constitution was promulgated. His ideas of establishing enlightened despotism and state centralization are most prominent in his management of the Kingdom of Sicily.

Then he turned his eyes to Germany, the native land of his fathers and ancestors. After the death of Henry VI, Otto IV of the Verf family defeated Henry VI's brother Philip and won the throne. But Otto IV betrayed his alliance with Pope Innocent III, and Innocent III turned to support Frederick and made him ally with the French king, opposing Otto IV's alliance with John of England. In 1214, at the famous Battle of Bovins, Frederick's alliance with France was victorious and King Otto IV was deposed. Frederick was crowned Holy Roman Emperor in 1220, and later surrendered the German throne to his son Henry and returned to Sicily. However, Frederick pursued a different policy in Germany from that in Italy. When the German princes had conflicts with the Rine City Alliance, he supported the princes in attacking the City Alliance and gave them more power, which aroused the dissatisfaction of his son Henry, and eventually turned against each other. Eventually, Henry rebelled against Frederick in 1234 and was defeated and deposed. Frederick appointed Conrad (Conrad IV) as King of Germany.

Frederick's conquest of Jerusalem was very interesting and was the only "Peace Crusade." He married Isabella, the heiress of the Kingdom of Jerusalem, in 1225. In 1228, through diplomatic tactics, excellent foreign language skills and negotiation skills, he obtained Jerusalem and its surrounding areas from the Egyptian sultan. In 1229, he crowned himself King of Jerusalem.

But Frederick's struggle with the Pope was extremely difficult and protracted. The power struggle between the emperor and the Pope was one of the themes of political life in medieval Western Europe, but the struggle between Frederick and the Pope had another meaning. Frederick's thoughts had a centralized element. He actively practiced his thoughts in Italy, based on the consolidated Kingdom of Sicily, and committed to controlling northern Italy, with the papal state sandwiched in the middle becoming the main obstacle. After Frederick ascended the throne, the two previous popes, Innocent III and Honorius III, were his guardians and teachers respectively. With their cooperation, Frederick achieved a series of victories. But starting from King Gregorian IX (1227-1241), the debate between religion and customs inevitably became the focus.

In 1227, Gregory IX expelled Frederick II and sent troops into Sicily, forcing Frederick to give up his good situation in Jerusalem and return to Sicily. As a result, Frederick defeated the papal army and forced Gregorie to restore his religion.

Since then, both sides actively developed their influence in northern Italy, and the Pope used the Lombardy Alliance to confront Frederick. In 1237, Frederick led his army into northern Italy, defeated the Lombardy League at the Battle of Cortenua, approached the border of the Papal States, and captured Sardinia, transplanting the centralized system he had established in Sicily to the occupied areas. King Gregory IX excommunicated him again. In 1241, Frederick invaded the Papal State and almost occupied Rome. Gregory IX died in anger.

In 1243, Innocent IV took over as Pope. He fled to Lyon, France, and used French power to confront Frederick (this was also a major turning point in the history of the papal state). In 1245, Innocent IV convened a religious assembly in France, recounting Frederick's crimes, excommunicated Frederick, and called on the monarchs of various countries to attack Frederick. Later, he attempted to bribe Frederick's close attendant to poison Frederick. Frederick tit-for-tat and issued an open letter to European monarchs criticizing the Pope's rule, triggering a major theological controversy. Supporters of both sides launched wars in Germany and Italy at the same time, and the results were mutual wins and losses. When the war was at a stalemate, Frederick suddenly died of illness in 1250. Soon after, the Hohenstaufen dynasty fell.

Frederick II's thoughts had factors that transcended the times. The first is his centralized thoughts, as mentioned earlier, and the second is his liberal tendencies in religion, literature and art, which is closely related to his growth in Sicily, a crossroads of multiple civilizations.

Although Frederick never broke away from his Catholic identity in his life, he confiscated church property in his territory and weakened the church's power. Most of the servants around him were Muslims (this was one of the reasons why the Pope accused him of being a "heresy"). He founded the first university in Sicily, the University of Naples, and hired scholars from all over the country to teach at high salaries. He himself is also known as the "first-class talent." Since the cultural and academic level of the East was higher than that of Western Europe at that time, most of the scholars he hired in universities and palaces came from the Middle East. He brings people of different faiths to live in harmony. He also favored dissecting corpses. His story with Saint Francis is widely told. When he invited Francis to come as a guest, he sent a beautiful woman to test Francis. Francis spread red coal under himself to restrain his desire. Frederick admired this and had a long talk with Francis all night on many religious issues.

Under the influence of Frederick, Italian literary and artistic scholarship was unprecedentedly active. Half a century after his death, Italy entered the great era of the Renaissance. Frederick fought all his life, but his main political influence was the decline of the papal states and the further expansion of the power of German princes. His position in the history of literature and art was higher than his position in political history.

Comment: Although Frederick II was involved in wars with the Pope and German princes because of his German royal status, he also served as king of Sicily and Jerusalem, two places that were the intersection of European and Middle Eastern civilizations of that era, making him an "outlier" among Western European monarchs. In that era, it was his "otherworldly" who could play a greater role in promoting cultural prosperity and historical development.