Considering the brutality of the siege, the Han army also recruited garrison divisions from the Central Asian allies and the Western Regions Protectorate to prepare for the attrition of personnel.

In June 213, the offensive and defensive battle of Mosul, which later became known as the "meat grinder of Mosul", began.

More than 200 field guns and 300 mortars of the Han army were prepared for half an hour, and most of the walls of Mosul, which had just been reinforced, collapsed in most of the places that were later reinforced.

The defenders at the head of the city suffered many casualties, and the Romans had never encountered such heavy artillery preparations when defending the city, and they had not even faced the scene of an artillery siege.

In the previous siege warfare, the opponent used trebuchets or trebuchets to bomb at most, and the opponent never used artillery to attack the city.

So the inexperienced Romans, the defenders exposed to the walls suffered a devastating blow, but fortunately the Romans were used to the use of auxiliary legions in the first wave of defense, and the regular troops were on standby under the walls.

The Romans immediately removed all the troops who were still alive from the city, and thought of digging anti-artillery holes under the city walls, which still had a strong ability to adapt.

Even so, the first artillery preparation of the Han army caused tens of thousands of casualties in the Roman auxiliary legions, almost reimbursing two complete legions.

The Roman emperor Caracalla sat on a throne in the palace of Mosul, pale and listened to the deafening sound of cannons and explosions coming from the city walls.

He didn't expect that when the artillery of the Han army attacked, it would be so powerful, and the city defense officer had already come to report the losses of the Romans just now, and the casualties of 10,000 people were still quite painful.

He is still glad that he didn't put the big guys developed by the Academy of Sciences on the city wall as soon as possible and keep them as killer weapons, which seems to be very wise.

Hearing that the cannon fire had gradually stopped, he got up and went to the city wall to have a look.

Macrinus, Lucis and the others immediately stopped their emperor, "Your Majesty, how precious your identity is, there is such a danger on the city wall, let's just go and take a look, you still stay here, it's safer." ”

"Get out of here, I just want to see how powerful the Han army is, you can also see, they have so many artillery, and so many shells."

"They are also vast world powers, why are their scientific and technological levels still ahead of us? We have inherited countless advanced technologies and ideas from the great ancient Greek civilization, and we are so far behind. ”

Caracalla shouted at Macrinus and the others, who, as a king, the supreme ruler of the Roman Empire, had supreme control over everything.

He was full of resentment towards this Han Empire that suddenly appeared in front of him.

He stopped his own development within the confines of the Rest Empire, and fought fiercely with his own legions, even gaining a slight upper hand.

Therefore, he will defeat the Han Empire at any cost, and prove to the world that only the Romans are the truly most powerful people in the world, and the Roman Empire is the largest empire in the world.

In the end, Caracalla, accompanied by many generals, climbed to the top of Mosul, and at this time, the Han army had begun to attack the city.

The siege methods of the Han army made the Romans refreshed. Under the cover of artillery fire, the Han army had dug a trench less than 200 zhang away from the city wall, and when the cannon sound gradually subsided, the Han army's siege troops had jumped out of the trench and rushed to the city wall with a ladder.

After the cannon fire stopped, the Romans began to rush to the city, but most of the dozens of ballistae that had been placed at the head of the city were destroyed by artillery fire.

The ballista is the most used defense and siege weapon by the Romans for hundreds of years, unlike the ballista of the Han Dynasty, the ballista of the Romans is wound with a winch twisting rope, a bit like a counterweight stone thrower.

The starting position of the Han army was less than 200 zhang from the city wall, and under the rapid running, they rushed to the city in a moment.

The ladder was quickly erected, and the selected daredevils began to climb up.

Caracalla saw such a picture, the centurions of the Roman legions, one after another, drew their bronze daggers, and shouted loudly for their Roman warriors.

In the battle to defend the city, the bow and crossbow of the auxiliary legion can finally be put to use, who made the protection of the Han army very low?

The Sabbatians were also driven up to the city by the Romans to play their part.

The Romans also dug some hidden pits at the head of the city, which were used to hold the head of the city and observe the enemy situation when the Han army was preparing for artillery fire, and the Romans' war wisdom was still very high.

The death squads of the Han army, under the bullets and crossbow arrows of the Romans, struggled to climb up.

In the trenches outside the city, a large number of Han soldiers used rifles to provide cover for the death squads.

Every second, Han Chinese and Romans fell.

On the ladder, there were many Han troops besieging the city, and the ladder at this time was not at all pushed by a few Romans, they could only blow it down with grenades.

The grenade exploded in the crowd of the Han army, and many people would be killed and injured by fragments.

And when they climbed halfway to the city wall, the Han army would also throw grenades at the head of the city, killing and wounding the Romans.

Such scenes were constantly played out on the walls of Mosul, and each section of the wall left behind two armies of warriors who had sacrificed a lot of money.

Seeing that he was at a stalemate, Lü Kang ordered mortars to fire at close range to suppress the defenders at the head of the city.

However, the Romans also quickly transferred their mortars to the city, and in turn suppressed the Han army, and the difference in the range of the mortars between the two sides was only a few dozen zhang, and finally evolved into mortar fire.

In order to reduce casualties, the Han army also began to send Central Asian Allied forces, Persian infantry, and Western Regions garrison divisions to the battlefield in turn.

Anyway, it was a hand-to-hand battle for the head of the city, which only required courage, and besides, these allies of the Han army were all equipped with a full set of firearms, unlike the auxiliary legions of the Romans, who were only half equipped with muskets.

Moreover, in the process of capturing the city, cold weapons are actually more suitable, and many of these allied troops are still wearing iron armor, which is more protective than the Han army.

And when the Han army finally attacked the city, a large number of Romans and Sabbatarians would surround it and engage in hand-to-hand combat.

This kind of offensive lasts for a day, and there will be tens of thousands of casualties on both sides.

And after dark, the two sides will have a tacit understanding to clean up the battlefield, the climate here is hot, and the dead body must be disposed of as soon as possible, otherwise it is very easy to cause an epidemic.

At this time, the Han army's strong medical support capabilities were reflected, and the lightly wounded soldiers would soon regain their combat effectiveness, and the seriously injured soldiers would also be saved because of timely treatment.

Therefore, although the casualties on both sides were close, the Han army did have fewer dead and more wounded, while the Romans, on the contrary, were subject to the backward technology and concepts of that era, and the seriously wounded soldiers basically ended up dead.

The Romans were also recruiting their allies, such as the Egyptians, the Sabbats, the Carthaginians, and the Gauls, and the legions of these allied armies also arrived in Mosul to join the Romans in defending the city.