23rd of March, 633, Istakhr
"My Shahanshah! Some disloyal subjects have rebelled against you and your will! Reports say they're trying to raise an army and march on Istakhr!"
This report came into Yazdegerd's ears quite unexpectedly. To explain, it came much sooner than he anticipated. Much sooner. That is, he had barely implemented the reforms, so this rebellion was a surprise. Whether it would be welcome one or unwelcome one was yet to be seen, depending on the state of the army Rostam was supposed to gather and on the state of the gathering itself. After he blinked a few times, he fully absorbed the report and started asking.
"Do you have full list of the rebel nobles? Who leads them? Where are they based?"
These were the common question any ruler would've asked. And Yazdegerd was no different in this case. The only thing ruler needs to know is who and where is against him. His servants would do the rest. In this situation, "servants" are meant soldiers and by "the rest" is meant go and die on the field of battle.
"Some nobles in the Sistan and Baluchistan regions, my Shahanshah."
Yazdegerd was surprised. If these were his only opponents, he had basically nothing to worry about.
"And, also, a marzban of Eastern Khorasan with his capital at Herat. He's the one leading the rebellion."
Yazdegerd's face turned sour. Herat was an important city in the Khorasan region. Main trade and population centre in the area. Not as great as Ctesiphon, but comparable to Istakhr. It was a city of great importance and even greater sphere of influence – it isn't needed to be said that those who control it control a great deal of power. So Yazdegerd had a pretty strong opposition. He had to consult this with Rostam.
"Thank you. You may leave. But bring me my spahbed first."
The servant bowed and left. Yazdegerd sat down and started scratching his head. If Rostam was able to form the army by now, he could crush them with little to no opposition, as, according to the reports, their army was in the stage of gathering. And Yazdegerd wanted to ensure they'll never gather. But if the reports were wrong, or if Rostam didn't gather sufficient troops yet, all of that would have to be thrown into fire. It was much tougher situation than Yazdegerd thought it would be. But as they say, "You reap what you sow."
"My Shahanshah, I came on your request."
Rostam showed in front of Yazdegerd out of nowhere, which surprised him. But he quickly regained his composition and started the discussion.
"How does it look with the army? Is it ready yet?"
"My Shahanshah, of course it is. And it waits on your command."
Of course it does. Rostam didn't let Yazdegerd down as always. And since the army is ready, the only thing that could go wrong was the validity of the reports. And Yazdegerd had to count with the possibility of them being wrong.
"My spahbed, reports of a noble rebellion have just reached me. I want you to lead the army against them."
He started walking around the room, looking him in the eyes whenever he had the chance.
"Reports say their army is yet to gather. It will be on you whether you'll trust these reports or not. I personally don't, but I am not the one experienced in warfare here. It is a great responsibility, but as my spahbed I believe you'll not disappoint me."
Rostam looked strangely at Yazdegerd, exactly between his eyes. They maintained this eye contact for a while, after Rostam kneeled.
"My Shahanshah, I shall lead your armies to a victory against those who dare defy your will."
Yazdegerd smiled mischievously, as if he watched some event beneficial for him unfold.
"I will give you The Immortals. You will need them. Send me weekly reports, and after you win and defeat the enemy, return not here, but to Ctesiphon. I believe I will be there when the time comes."
"My Shahanshah, you plan to return there? Did the people finally accept you?"
"I don't know. And if they didn't yet, they'll quickly have to."
After hearing that, Rostam bowed and left the room, as he always did.
---
Southern Mesopotamia, March 633
"General Khalid! I bring news! The rebellion was successful! Sheik of Herat has rebelled against the child-emperor."
Some messenger ran to Khalid ibn al-Walid, the general leading the Arab campaign against the Persians. The news he just heard were key to his plan – destabilizing the country from within and then attacking the weakened child-emperor for a quick and successful war. In the name of God, of course. If the reports were true, and he believed they were, they could begin their campaign. After marching through the Lakhimid kingdom, once a Persian client state, they arrived into the Mesopotamia, land rich in everything a man could imagine. They say that if you can't find something there, it simply doesn't exist. When Khalid received the good news, he proceeded with his goal of taking Hira, an important city on the shore of Euphrates. Once he would capture Hira, he would continue to Peroz-Shapur and eventually, through al-Quadisiyyah into Ctesiphon. It was a good plan, and with Khalid being a military genius, there wasn't much that could stop him.
Khalid still had the messenger in front of him, thinking of using him.
"Bring me a scribe."
The messenger left as quickly as he arrived back, this time with a scribe with him.
"Here. Sit here and write."
Scribe sat down at the provisional table Khalid had for him prepared.
"Let these letter be sent to every Persian general and commander in the Mesopotamia. Let them see the mercy of Allah. Now, write this:
In the Name of God, the Most Compassionate and Merciful. Khalid ibn Walid sends this message to the satraps of Persia. Peace will be upon him who follows the guidance. All praise and thanks be to God who disperses your power and thwarted your deceitful plots. On the one hand, he who performs our prayers facing the direction of our Qiblah to face the sacred Mosque in Mekkah and eats our slaughtered animals is a Muslim. He has the same rights and duties that we have. On the other hand, if you do not want to embrace Islam, then as soon as you receive this message, send over the jizya and I give you my word that I will respect and honor this covenant. But if you do not agree to either choice, then, by God, I will send to you people who crave death as much as you crave life."