A few days after the pact with the Median nobles, Kourosh took the first practical step to turn this political union into a military reality.
On the great plain of Pasargadae, he read a decree that was destined to change the military history of the region forever.
In a symbolic and intelligent move, Arash, the young and innovative Persian commander, and Harpak, the experienced and respected Median general, were appointed as the joint commanders of the army.
This command created a great challenge and a unique appeal.
Two completely different military cultures now had to be melted in the furnace of a common goal and be transformed into a new alloy.
In the first few days, these differences showed themselves like rocks in the path.
The Persian soldiers, who were accustomed to iron discipline and unquestioning obedience, were exasperated by the constant clamor and boasting of the Median soldiers.
Arta, while looking with frustration at a group of Median horsemen who were racing with loud laughter, growled to Bahram:
"Look! It is as if they have come to a feast, not a military camp!"
"How can one build a shield wall with these people?"
On the other side, the experienced Median soldiers looked at the complex tactics and repetitive drills of the Persians with a mocking eye.
Mazares, while watching the training of a hundred-man Persian unit, said to one of his commanders:
"Are they dancing or are they fighting?"
"A real warrior makes his decision on the battlefield, not by following the sound of a drum!"
This gap stemmed not from enmity, but from a deep difference in the philosophy of war.
Kourosh, who had predicted this challenge, found the solution not in speeches, but in action.
He arranged a joint maneuver.
A Persian Hezarbod, under the command of Bagpat, was tasked with defending a hill.
A Median Hezarbod, commanded by one of Mazares's sons, was tasked with capturing it.
The battle began.
The Persians, by forming a flawless phalanx and using their archers, repelled all the head-on attacks of the Medes with complete discipline.
But the Medes, instead of direct attacks, used their individual genius.
Small groups of their horsemen, using their knowledge of the mountains, found difficult paths and attacked the defenders from the flanks.
These harassing and unpredictable attacks faced the iron discipline of the Persians with a serious challenge for the first time.
They learned that discipline alone is not always effective against creativity.
On the other side, the Medes also learned their lesson.
Every time one of their small groups succeeded in creating a breach in the Persian lines, they were immediately met with a coordinated and orderly counter-attack from the reserve units and were pushed back.
They understood that individual courage, no matter how great, will ultimately be defeated in the face of a coordinated war machine.
After hours of mock battle, the maneuver reached a stalemate.
Neither side had been able to achieve a decisive victory over the other.
That night, beside the campfires, the silence between the two groups was broken.
The Persian soldiers looked at the individual skills of the Medes with respect.
The Median soldiers spoke with astonishment of the discipline and teamwork of the Persians.
Arta went to one of the Median horsemen and asked him about a specific technique for spearing from horseback.
In another corner, Mazares was discussing with Arash how to combine the power of the Median cavalry with the Persian shield wall.
This was the moment of the true birth of the Shahanshah's army.
Not on the battlefield, but beside the campfires.
Where two warrior peoples, by setting aside their pride, began to learn from each other.
They gradually realized that by combining Persian discipline and Median courage, they could become a force that no army in the world would be able to stand against.