All of the above combined, the Roman Empire had a momentum of revival, and Caracalla also had the atmosphere of a bright king.

In real history, this is a short-lived emperor who was reckless, liked wars of aggression, and was finally assassinated by his subordinates on the front line.

But now, instead of invading others, Caracalla was careful to be aware of them, and the Roman navy was operating in the Mediterranean, attacking and harassing the provinces on the southern coast of the Mediterranean occupied by the Persians.

It even gathered the full forces of the Eastern Mediterranean Fleet and the Western Mediterranean Fleet of the Roman Navy to carry out a sneak attack on Alexandria, but it ended in failure.

The main reason is that after Sima Yi occupied Alexandria, he immediately built a coastal battery at a suitable location outside the port, and used field artillery before the arrival of real fortress artillery.

At the same time, Sima Yi got in touch with Lu Su, who was stationed in the port of Suez, and told Lu Su about his idea of building a fort to guard Alexandria.

Lu Su was very supportive and thought it was a very strategic decision.

Lu Su not only rode from Suez to Alexandria on horseback, but also brought naval professionals to guide the construction of coastal forts.

Lu Su also ordered his men to disassemble four of the 10-inch guns and eight 8-inch guns on the Imperial-class sail battleships, and load them into horse-drawn wagons with the matching shells and the gunners to Alexandria.

Officers of the Navy studied fortress defense at the Naval Officers' Academy, and specialized in the construction and construction of coastal batteries.

They revised, revised, Sima Yi's original design drawings, and re-planned the reasonable location of artillery of different calibers, the protection of gun emplacements, and the cover of land directions.

Sima Yi believed that the Romans would not sit idly by after learning the news of the Han army's excavation of the Suez Canal.

With the character and tradition of the Romans, they would definitely take the initiative to attack, and Alexandria, which was controlled by the Han army, was the first choice, especially when the Mediterranean Sea was still firmly controlled by the Romans.

Because the fort was on land and had a solid foundation, many techniques that could not be used on warships were put into practice.

First of all, the gun emplacements of the turret were equipped with a base that could be rotated, so that the fortress guns could fire in all directions without dead ends.

Even if the enemy attacks from land, the fortress artillery can also provide fire support.

Second, the guns were equipped with armor domes thick enough to prevent shells falling from above, and armoured breastwalls were built in the direction facing the sea.

Such a semi-open shooting can not only provide effective protection, but also do not affect the drift of gunpowder smoke and combat efficiency.

In August 215, after careful preparations, a Roman navy of unprecedented size set sail from Taranto, joined by warships and transports along the way.

The Roman Empire's navy was the largest Roman fleet since the Roman Empire, but its flagship was only a six-oared warship.

Since Rome entered the imperial era, the huge naval warships of the Republic era have been decommissioned and dismantled, because the Roman Empire has no significant opponent in the Mediterranean.

The conquest of the Egyptians and Syrians allowed the Roman navy to dominate the Mediterranean, and the Senate naturally did not allow a navy to remain as large as a war.

The Roman emperor was also more willing to devote his limited budget to wars against the barbarians of the north and the aliens of the east, and preferred to build and arm mighty Roman legions rather than naval ships that could not find opponents.

Therefore, the giant ships of the Roman Imperial Navy were decommissioned and dismantled, except for the Central Fleet in Naples, which also maintained several five-reels and one six-oars flagship, and maintained them regularly, there were no such giant ships in other subfleets.

The largest warship they were generally equipped with was the 50-meter-long triremes, with a tonnage of no more than 50 tons.

The five-, six-, and even seven-oared warships that were originally mothballed had long since decayed due to their age and improper maintenance.

There was also no time to rebuild these huge ships, and there was a shortage of skilled shipbuilders in sufficient numbers.

This kind of huge ship can only be built in the Roman Empire at the shipyards of Naples and Syracuse.

So this time the huge fleet assembled by the Romans, only the flagship was a six-oared battleship, and in addition there were only ten five-oared warships, and the rest were thirty four-oared warships and sixty triremes, as well as fifty double-oared warships, and a hundred transports.

However, with more than 200 ships, it was still the largest fleet of the Roman Empire, and they also carried a large number of marines, three Roman legions, and three auxiliary legions.

The commander of the naval fleet was the commander-in-chief of the Imperial Navy, Publius, and the commander in charge of commanding the landing force was none other than Marcus, who became famous in the Great Nicaea Retreat.

Although Marcus was unwilling to accept this work from the bottom of his heart, His Majesty the Emperor personally ordered it, and Lord Lucis strongly recommended it, so he couldn't do it!

Of course, he was full of confidence in the Imperial Navy, the Han and Persians did not have any naval power in the Mediterranean, and I heard that they were building ships, but they had not yet been launched!

He did not have confidence in the army corps under his command, and six corps wanted to take Alexandria? It's a fantasy.

After a few days of sailing, the fleet reached Crete, where the weather and sea conditions in the Eastern Mediterranean have been good lately, with clear skies and calm waves.

Publius sent a reconnaissance ship disguised as a merchant ship to reconnoiter the current situation in Alexandria.

After a day and night, the reconnaissance ships returned, and Alexandria was as usual, with many merchant ships entering and leaving the port, and it was still a busy scene of the largest port on the southern shore of the Mediterranean.

No traces of warships have been found, and of course neither the Han nor the Persians have warships in the Mediterranean, but I heard that they are being manufactured in the shipyards.

One of the main objectives of this attack on Alexandria was to destroy the warships under construction in the shipyard, get the design drawings, and preferably capture some technicians and shipbuilders, which Rome also needed in need.

Purbrius consulted the guide in the fleet, the captain of an Imperial Navy warship stationed in Alexandria, and determined that tomorrow evening would be a good time for the tide to rise, and the largest six-rorees would easily dock.

The Roman fleet began to make its way towards Alexandria, and all ships in sight, regardless of nationality, were to be detained and released after the war was over.

Those who dare to resist and escape will be killed! They had to keep it as secretive as possible, so as to catch the Han people off guard.