The feudal system of the European Middle Ages is similar to China's Spring and Autumn Warring States Period, which divided the nobility into fifth-class titles, so China translated the European noble titles as dukes, marquises, uncles, sons, and men according to the fifth-class titles of the Spring and Autumn Warring States Period. The Duke, Marquis, and Earl each ruled the Caiyi, which was in fact equivalent to a semi-independent small country. Such states tended to be dependent on a more powerful kingdom, but maintained considerable autonomy under that kingdom. At one time, the political map of Europe was like a sky full of stars.

Wales in England and Catalonia in Spain were historically principalities ruled by dukes. After the Council of Westphalia in 1648, the Holy Roman Empire of Germany consisted of more than 300 states and more than 1,000 knightly territories. With the rise of absolutist monarchy in the 17th and 19th centuries, the technology of standing army, statute law, indirect taxation, and technocracy began to gradually emerge. The original customs, languages, habits, and traditions of various states and cities have increasingly lost their autonomy.
Since then, the standing army under the command of the central government of the country has replaced the armed forces composed of knights of the feudal nobles everywhere, the central government has begun to directly tax the people to replace the traditional feudal tributes levied by the layers of feudal lords, and the technocrats selected through the civil service examination have replaced the hereditary nobles under the feudal system to hold important positions in the government... The culmination of this series of changes is the strengthening of centralized power. Principalities ruled by dukes, as well as smaller marquisates, earldoms, etc., as products of the feudal system, mostly withered away in such a situation.
At present, the only remaining European principalities are the Principality of Andorra, the Principality of Monaco, the Principality of Liechtenstein and the Grand Duchy of Luxembourg, four independent sovereign States recognized by the United Nations, and a so-called Principality of Sealand that is not recognized by the international community. The kingdoms of Britain, France, and Germany, which originated from medieval kingdoms, do not seem to be very large today, and principalities one level lower than the kingdoms are even smaller. Luxembourg, the largest of the four principalities of Europe, has an area of only 2,586.3 square kilometers and a population of just over 600,000, while the smallest monaco has an area of only 2.08 square kilometers and a population of less than 40,000.
The forbidden city in Beijing covers an area of 720,000 square meters (0.72 km2). Monaco's territory is no less than three forbidden cities. On average, Monaco has more than 19,000 people per square kilometre. This population density is second only to Macau in China among more than 200 countries and regions in the world. None of the world's sovereign countries have surpassed Monaco's population density. Monaco, a small projectile country, is surrounded by French territory on the east, north and west, and only the southern part faces the Mediterranean Sea, so why didn't France directly annex this small projectile country?
It is said that Monaco was originally a castle built by the Phoenicians, but it was gradually dilapidated during the long wars that followed, and it was not until Genoese that the Castle of Monaco was rebuilt in Genoa in 1215. In 1297, François Grimaldi disguised himself as a Franciscan monk seized the Castle of Monaco, thus beginning the family's 700-year intermittent rule over Monaco. Monaco became an independent principality from 1338 onwards, but in 1525 the Spaniards made Monaco their own protectorate.
At that time, Spain was not the second- and third-rate countries it is today: Spain and Portugal were the two great powers that dominated the sea, while Britain and France did not have enough strength to compete with Spain at that time. Under the long rule of the Spaniards, Monegasque discontent with Spain is also quietly growing. In 1588, Spain's hegemony began to gradually decline after the Anglo-Spanish War. This gave the Monegasques hope of escaping Spanish rule. On 14 September 1641, Monaco expelled the Spaniards by allying itself with France.
It turns out that Monaco's move is to drive the wolf and the back door into the tiger: France is actually more dangerous than Spain - even if the Spanish rule is arbitrary, after all, Spain and Monaco are still separated by a certain distance, so under the traffic conditions at that time, Spain will still retain some autonomy for the Monegasque people. Spain's rule over Monaco was a model of a protectorate: although Monegasque's domestic and foreign affairs were subject to Spain, it nominally retained its identity as a state. When the French arrived, they simply annexed Monaco.
After the outbreak of the French Revolution on July 14, 1789, Britain, Prussia, Austria, Tsarist Russia and other countries immediately formed an anti-French coalition to intervene in the French Revolution. The First Republic, established after the French Revolution, and later the First French Empire established by Napoleon fought against seven anti-French alliances. In October 1813, Napoleon lost the battle with 180,000 men in Leipzig in Germany against the Russian Empire, the Austrian Empire, the Kingdom of Prussia and other countries. On 31 March 1814, Napoleon was forced to announce his abdication after the victorious pursuit of Paris.
The Monegasque seized this favorable opportunity to declare autonomy decisively. This secession from France also allowed Monaco to take the opportunity to expand its territory a lot: in fact, Monaco's total expansion area during this period was only more than 20 square kilometers. This is certainly not a big one to us, but it is the largest area in monaco history. After Monaco declared its autonomy, it sought protection from the Kingdom of Sardinia: at that time, Monaco and France were separated by savoy and Nice, which belonged to the Kingdom of Sardinia.
The Kingdom of Sardinia was one of the more powerful states in the Mediterranean at that time: prosperous in commerce and militarily powerful. Monaco, protected by the Kingdom of Sardinia, was able to survive for a while. In the mid-19th century the Kingdom of Sardinia launched a war to unify Italy. During this process, the Kingdom of Sardinia sought support from France in order to expel the Austrians entrenched in the northern part of the Apennine Peninsula. For this reason, the Kingdom of Sardinia ceded savoy and Nice to France. Monaco, which had lost its barrier, was completely under siege from French territory.
In 1860 Monaco was placed under French protection. Although Monaco at this time was still reluctantly retaining its independent status, in practice most of the territory was no longer within the bounds of its jurisdiction. Fearing that France would eventually annex itself, the Monegasque royal family found the old rival of the newly unified Kingdom of Italy and France, Britain, to mediate. In 1861, Monaco sold 90% of its territory to France for a low price of 4 million francs, and at the same time established a customs union with France.
France also let Monaco go after receiving 90 per cent of monaco's territorial and tariff benefits. In this way, Monaco ceded land in exchange for France's recognition of it as an independent sovereign state. After the 20th century, France continued to adjust its relations with Monaco, thus placing almost all aspects of Monaco under French administration. The independence, sovereignty and territorial integrity of Monaco, which lacks an autonomous defence capability, are guaranteed by France, and Monaco is committed to exercising its sovereignty with full respect for France's political, economic, maritime and military interests.
So Monaco's so-called independence is actually only relative. In fact, such a small country is doomed to be unable to truly become independent. Today,comunaco, despite being nominally a country, is in fact highly controlled by France in terms of its internal and foreign affairs. Monaco's treaty with France even stipulates that the Monegasque royal family will automatically be incorporated into France as soon as there is no male heir. Monaco has come at a great cost in surviving france's eyes, and the obedient Monaco has always been in line with French interests.
So why should France annex a place that wasn't enough to plug its teeth? Monaco thus maintained its relatively independent status. Monaco's independence from French protection in 1861 came at the expense of ceding more than 90 per cent of the country's territory. After independence, Monaco was once only 1.57 square kilometers of territory. In order to alleviate the contradiction between economic development and the shortage of land resources, Monaco has constantly turned to the sea for land. Today, Monaco has acquired 0.63 square kilometers of land reclamation.
This corresponds to 28.6% of Monaco's total area and 88 standard football fields. The Stade Louis II in Monaco is a stadium built entirely on top of reclaimed waters. For fifteen years, from 1998 to 2012, the stadium was the venue for the European Super Cup. Covering an area of 160,000 square meters, the Port of Hercules, as the only deep-water port in Monaco, can berth more than 700 large and small ships. The port of Hercules has been continuously expanded since the 1960s. On 26 August 2002, a floating terminal weighing 160,000 tons, 352 metres long, 28 metres wide and 19 metres high arrived in Monaco.
The behemoth of this reinforced concrete structure is connected to the port of Hercules by a 700-ton stirrup. To this day, the reclamation of land in Monaco continues. Prince Albert II of Monaco has set up a place adjacent to the Monte Carlo Casino as a new reclamation area. The new reclamation, which extends at least 50,000 square metres to the ocean and is expected to cost $15.9 billion, will be a premium living area with yacht berths, offices, public services and upscale apartments. Monaco, though small, is extremely wealthy.
Monaco's GDP totaled $7.185 billion in 2018, which is definitely a fairly high figure for a country with a total population of less than 40,000, and the per capita income of Monaco people can also be among the highest in the world. For many years, the Government of Monaco has adopted a diversified, high value-added and pollution-free economic development approach, focusing on promoting the comprehensive development of the tertiary industry. This is actually determined by Monaco's actual national conditions - limited by the narrow land area, the resources required for various industrial and agricultural production are extremely limited, so the development of the tertiary industry is a realistic choice for Monaco based on its national conditions.
Today, Monaco's real estate, advertising, insurance and consulting industries are developing rapidly, especially in tourism and finance. Tourism is one of Monaco's pillar industries: Monaco has both medieval-style streets and royal palaces, as well as Europe's oldest large casino and luxury hotels in its surroundings, as well as tropical botanical gardens and maritime museums. The famous tennis open and the Formula 1 race will make this small country a hot spot in the world. Monaco also hosts cultural and sports events such as the Monte Carlo International Acrobatic Festival and the International Flower Festival to attract visitors from all over the world.
As of 2017, Monaco has built 12 star-rated hotels, 101 restaurants, a total of 2298 rooms and 4596 beds. Since the Government of Monaco does not levy personal income tax, it has attracted a considerable number of wealthy tax-avoidant immigrants. Of course, many people may know About Monaco because of the Princess of Monaco: Grace Kelly, the queen of the 27th Academy Awards in 1956, married Prince Rainier III, the head of state of Monaco. Today, Monaco's current princess, Charlene Vestock, is still at the top of the world's fashion trends.