In May 215, at the same time as the crown prince Lü Kang led the army back to Chang'an, the Suez Canal Construction Headquarters was formally established, and the Egyptian Governor Sima Yi served as the commander-in-chief, and began to excavate the Suez Canal.

Tentatively, the canal will be dug from the port of Suez on the Red Sea coast in the south all the way north to Port Said on the Mediterranean coast in the north.

Of course, Port Said is still only a small fishing port, but in the long run, Port Said will become one of the largest ports in the Mediterranean, comparable to Alexandria, thanks to the opening of the canal.

The project is very large, the total length of the canal is more than 300 miles, but it is necessary to borrow the isthmus landform and several lakes of different sizes, and the overall construction is not difficult, not to mention the help of explosives.

The only uncertainty is the elevation of the sea level at both ends of the canal, but this can also be solved by locks, but it is only more difficult and time-consuming.

Lü Bu had already made up his mind to build and open the Suez Canal, which was also to allow the navy of the Han Empire to enter the Mediterranean Sea at the closest distance and prepare for the future attack on Rome itself.

Now, the First Han-Luo War has ended, ending in the defeat of the Roman Empire, which lost its territory in the east, leaving only the territory of the European part to the west of the Strait.

The Persian Empire, with the support of the Han army, conquered all the Roman provinces of North Africa, including Cyrenaica, Africa, Numidia, and Mauritania, and the entire southern coast of the Mediterranean Sea was under the control of the Persian Empire.

The Persian Empire is now working hard to develop its navy, trying to withstand the enormous pressure of the powerful Roman Empire's navy before the Han Empire's navy enters the Mediterranean.

The navy of the Han Empire transferred some advanced shipbuilding technology and navigation technology to the Persian Imperial Navy, such as keel shipbuilding, watertight compartment technology, and navigation compass.

The shipyards of the Han Dynasty also sent engineers and technicians to help the Persians build the shipyards, guiding them in the construction of the first galleon.

The construction of new ships was very fast, and although the Persians could not build ships, they occupied areas with many descendants of the Greeks, who still had great shipbuilding skills, but lacked advanced technology and ideas.

So in less than a year, the 500-ton galleon built by the Persians was launched in Sidon.

At the same time, the shipyards of Alexandria, controlled by the Han, also built a 500-ton galleon, and most of the craftsmen here were transferred from China, as well as many local workers.

When the cannon was mounted on a galleon for a trial voyage in the Mediterranean, the Roman spies were astonished and immediately reported the discovery to the emperor and senate.

After the Romans built the artillery, they also thought of installing it on the warship, but they did not think about how to arrange the position of the cannon.

Everyone was surprised when the Roman spies put the sketches of the Han galleons in front of the emperor and the senators, and the Romans relied mainly on manual rowing and rarely used sails.

Of course, this also has to do with the environment in which they live, and the sea conditions in the Mediterranean are still too calm compared to the Pacific and Indian Oceans, and the sails are useless.

Moreover, the traditional mode of naval warfare in the Mediterranean is still dominated by collision and broadside warfare, and whoever has a flexible warship and a strong army will have the upper hand.

Therefore, the Romans preferred to use triremes or oars ships, which were both mobile and could carry enough marines, and the larger ships were long since obsolete.

The structure of the Roman warships also determined that they had no place to place their guns, so they could only be placed on the open deck, because the lower decks were filled with oars, there was no space, and the height of the Roman warships was also low, and there were not so many decks.

Seeing the galleon of the Han army, Caracalla immediately ordered the Academy of Sciences to develop and imitate the style of the Han army's sailing ships, and to hurry up.

The Romans already knew that the Han Chinese were building canals, whimsically planning to connect the Red Sea and the Mediterranean.

Of course, if this canal is really repaired, then the Han navy, which dominates the Indian Ocean and dominates the East, will continue to enter the Mediterranean Sea through the canal.

The reason why the Han Chinese stopped their westward expansion was that they were afraid of the Romans' powerful naval power in the Mediterranean, and they waited for the moment when they would take control of the Mediterranean.

Existential crises can often greatly stimulate human potential, and the Romans have developed military science and technology and the production of weapons and equipment by leaps and bounds under the threat of the Han Dynasty.

They had already made single-shot breech-loading rifles and copper-cased bullets, and the technology of smelting steel had improved rapidly with the help of the Sabbatarians, and a large area of bronze equipment that the Romans were proud of.

Yes, after the fall of the Resting Empire, there were many resting nobles and scholars who did not want to be ruled and enslaved by the Persians, and they managed to escape across the strait and into the Roman Empire.

The Romans certainly welcomed those who could bring wealth and advanced technology to Rome, and they used them for those who had real talents.

The Senate approved Lucis's proposal to allow His Majesty the Emperor to recruit and form more Roman legions, and to relax the policy of becoming a Roman citizen in order to expand the number of soldiers.

One Roman legion after another was formed, and the entire European continent, in all the Roman-controlled provinces, was engaged in fanatical propaganda, as if tomorrow was the end of the world, and the Han and Persians were the devils who destroyed the world.

Even the northern barbarians, who had been fighting against the Romans for many years, stopped the war with the Romans, and some even joined the Roman legions.

Different skin colors and different races naturally become the devil in their minds.

In Italy itself, one military factory after another sprung up, and a large amount of ore resources were sent to Rome from all corners of the European continent through the Romans' post roads.

All Roman citizens were mobilized, and the young and strong naturally joined the legions, participated in military training.

The old, the sick and the disabled, as well as a large number of Roman women, were also organized to do what they could.

Under the great pressure of the danger of losing the country, the Roman nobles and noblewomen who only knew how to enjoy and lived a luxurious life in the past also put down their identities and consciously participated in the work.

His Majesty Caracalla, Emperor of the Empire, led by example by donating a large amount of his personal property to build new equipment, and the senators of the Senate and the great merchants of Rome followed suit.

Even the priests of the temple gave up most of the temple's property to support the empire's military expansion, because they had heard that these Han Chinese and Persians were pagans who had come to destroy their descendants.

Many tax officials and temple priests were on the streets preaching about the crisis of the empire, the crisis of faith, collecting donations from people and asking them to help the country and their gods through the crisis.

The people who responded to the donation were so enthusiastic that even the beggars would donate the last copper plate on their bodies.