In July 1859, the Treaty of the Four Nations of Mexico City was signed in Mexico City. Because four countries were involved, all four countries sent heavyweights to the ceremony of signing the treaty.

The Treaty of the Four Nations was signed directly in Chapultepec Castle outside Mexico City, witnessed by representatives of the United Kingdom, the United States, Central American countries, and the Catholic Church.

However, when the contents of the treaty were read out publicly, the representatives of these countries were in an uproar.

Under the Treaty of Mexico City, the Catholic Church, France, Spain, the Chinese Empire, and Central America recognized the establishment of the Mexican Empire. The first part of the treaty is first and foremost related to the Mexican Empire and the Church, reiterating the provisions of Article 3 of the Federal Constitution of Mexico of 1824, which states that the state religion of Mexico was and will always be Roman Catholic, and that the activities of other religions in Mexico are prohibited, and that the existence of members of the Congregation is strictly prohibited at the top of the Mexican central and local governments, and that all the constitutions formulated by the former liberal government, which you originally restricted and suppressed the Church, are overturned, and that the confiscated church property is to be restored. The personal property and personal rights of Catholic clergy are highly protected. Of course, these regulations on the Church and the Mexican Empire and Emperor Maximilian have not yet attracted everyone's attention, but the following provisions are quite vigorous.

The second part of the treaty stipulated that the Mexican Empire, with the French Empire as its suzerain, received assistance from France and Spain, and was preparing to jointly recover the southern province of Central America, which was originally part of Mexican territory, that is, in 1838, it was divided into five countries: Guatemala, El Salvador, Nicaragua, Honduras, and Costa Rica. At the same time, a supplementary agreement stipulated that Guatemala and El Salvador would return to the Mexican Empire, while Costa Rica would be placed under the Viceroyalty of French Guiana, and Honduras and Nicaragua would return to the Kingdom of Spain.

The third part of the treaty dealt with the relationship between the northern territories of the Mexican Empire and the Chinese Empire, which divided the northern states of Baja California, Baja Canifoni Sur, Sonora, Chihuahua, Sinaloa, Durango, Coahuila, Nuevo León, and Tamaulipas and sold them to the Chinese Empire as territories in the Americas. It was agreed that the border between the two countries would be 40 kilometers from Mazatlan in the west, about 40 kilometers from Feresny in the middle, and 60 kilometers from Victoria City in the east.

Considering the financial crisis of the Mexican Empire, the Chinese Empire paid the Mexican Empire 30 million serailla, or about $30.84 million, as compensation. But at the same time, in return, the Chinese Empire, like France, had the most favored nation status in the Mexican Empire, such as trade and mining.

As soon as the contents of the treaty were made public, not to mention the envoys of the Central American countries who came to witness the treaty, and even the representatives of Britain, the United States, Portugal, and the Netherlands were shocked and expressed their opposition one after another, and strongly demanded that the four countries abolish the "Four-Power Treaty of Mexico City" that they had just signed, and wait for them to report to China for discussion and then reformulate the terms. However, a large group of French and Chinese soldiers appeared, with bright bayonets and cold barrels, and expelled the troublesome representatives of Honduras and Costa Rica from Mexico City.

Almost the next day, the President of the Republic of Guatemala announced his resignation and declared that the Republic of Guatemala had been annexed to the Mexican Empire. On the third day, the President of the Republic of El Salvador was killed in an accident, and the new interim President announced that El Salvador had been annexed to the Mexican Empire.

At this point, everyone understands that Guatemala and El Salvador have long been controlled by Mexico and France.

On the third day of the signing of the treaty, more than 4,000 French troops, 2,000 Spanish troops, and nearly 10,000 Imperial Mexican troops were sent from Chiapas, the southernmost state of Mexico, into Guatemala, which had long been declared to be incorporated into the Mexican Empire, and then continued southward, dividing troops into Honduras and El Salvador, and further sending troops to Nicaragua and Costa Rica. How many troops can resist these small countries in China and the United States, even if they want to unite, it is already too late, and in less than a week, they will be occupied by the forces of the three countries.

At the same time, in the northern region of Mexico, the 20,000 expeditionary forces of the Chinese Empire also began to sweep.

Baja California and Baja California Sur had been occupied by the Pacific Fleet long before the capture of Mexico City, while Sinaloa had been captured by the captives who occupied Mazatlan.

Within a week of the signing of the Treaty of the Four Nations in Mexico City, the armed forces of the north-central states of Mexico, which occupied the southern states of Sonora, Chihuahua, Durango, and Coahuila, withdrew from the territory of the Empire of Mexico and marched south into the territory of the Empire of Mexico, following the orders of the new Mexican Emperor Maximilian and the conservative general Tomás Messila, who had been promoted to commander of the Imperial Mexican Army. At the same time, conservative figures in these states, especially the Church, sold their fields and estates and moved their families south into the Mexican Empire. And for these, the Chinese Imperial Expeditionary Force was also happy to see it, and without the slightest difficulty, they all allowed it to go, and even in the face of the huge wealth they carried, they did not intercept it.

But the northeastern state of Coahuila, Nuevo León and Tamaulipas are home to Mexican liberal forces, and Juárez, who fled from Mexico City, and the more than 8,000 Mexican liberal troops he gathered along the way are also stationed in Monterrey, Nuevo León. Nearly 4,000 Mexican liberals were also stationed in the city of Victoria, Tamaulipas, ready to rely on these two large cities to fight to the death against the invading Chinese imperial captives.

I have to say that their abacus is really done. Because of the unfamiliar terrain, coupled with the lack of many intelligence sources, after all, the language barrier, Peng Yulin only cared about conquering the territory of the northern states, dispersed his forces, and divided the 20,000 expeditionary force into five forces to march together, although he soon occupied all the northern regions such as Sonora, Chihuahua, Sinaloa, and Durango, but encountered obstacles in Monterey City and Victoria City. Of course, the main reason for the disadvantage of the siege was that there was not enough ammunition for those special weapons, and the number of incendiary bombs was not enough.

After sacrificing nearly 300 soldiers of the capture army, Shi Zhenji led the four main regiments of the 21st Division to occupy Victoria City. Lin Qirong also led three infantry regiments of the 11th Infantry Division to make a detour to Monterrey, completely blocking the retreat of Huarez's army to the north.

At this time, Peng Yulin led other expeditionary force soldiers to control all the ceded northern states of Mexico, mobilized the main force to reinforce Lin Qirong, and besieged Monterrey.

As he was about to storm Monterrey, U.S. Secretary of State Lewis Cass rushed to Monterrey from the U.S. border to lodge a solemn protest with Peng Yulin, declaring that the attack on Monterrey and Mexican President Juárez was an act of aggression.

Peng Yulin immediately sternly refused through an interpreter, solemnly informing him: Huarez is a Mexican rebel who fled into the territory of the Chinese Empire after being driven out of Mexico by the legitimate Mexican government, and also captured the imperial city of Monterey for aggression. In view of the special reasons, it is hereby urged to withdraw from the city of Monterrey within three days and from the territory of Nuevo León of the Chinese Empire within a week. At the same time, Peng Yulin warned US Secretary of State Lewis Cass not to interfere in the internal affairs of the Chinese Empire, otherwise, it would be regarded as a declaration of war against the Empire, and the Chinese Empire would unite with France, the Mexican Empire and other countries to impose an economic and trade blockade against the United States.

At this point, Secretary of State Lewis Cass, who has always been tough on foreign affairs, fell silent.

In the face of the originally backward countries of the East, they have suddenly risen and suddenly appeared near the United States, and they have also invaded a territory, which he does not tolerate. But in recent years, the United States has always regarded it as an ally of general trading partners, especially the import and export of overseas trade, and the trade volume with the Chinese Empire has accounted for a quarter of the total trade volume of the United States, except for the United Kingdom, it is almost the largest trading partner, and unlike the British trade deficit, the United States now has nearly 10 million dollars in trade profits from this Eastern Empire every year, so even if Lewis Cass is tough, he has to soften. What's more, the United States is not fully prepared at all, and they still have France behind them, and he can only reiterate his solemn protest again before he clearly gets a statement from his big brother, Britain.

Seeing this, Juárez of Monterrey knew that the United States could not declare war on a rising power for the sake of its remnants and the fugitive Provisional Government without adequate preparation. And without the help of the American army, their defeated deserters could not hold Monterrey City at all, not to mention that even if they held Monterrey City, it was just an isolated city, and without supplies, it would be defeated sooner or later.