Piruz Khosrow, renowned general and leader, experienced aristocrat and landowner was, yes, surprised. Very surprised. Not in a good way. Instead of city, opening its gates and welcoming them as their saviours from the Göktürk menace, while its marzban welcomed them personally, he saw a city in despair, crying for help and awaiting release. Göktürks moved much quickly than he anticipated and besieged Merv before he even got there. Inside, he blamed himself for becoming soft and buying the soldiers the wine, as that extra baggage only slowed them down. But now was not the time to blame yourself. The Göktürks seemed to not notice him, as their camp was relatively calm and quiet, and their soldiers surely didn't look like they were preparing to fight. He immediately relayed the command to stop marching and lay low to not be spotted. He then observed their camp for a while, communicating with other commanders and discussing what to do. After a while he relayed last command. Prepare for fight.
Piruz had the moment of surprise in his hands, even though he was outnumbered with most likely poorer troops. But his soldiers were full of elan, and morale was on all-time high. They had the will and courage to fight, already sharpening their spears and sabres. Piruz discussed the strategy of the attack. They would use the moment of surprise to attack the camp and try to wipe out as many of them as possible before they would be able to regroup. Then, Piruz had to risk a bit. He relied on the city garrison, which was around three thousand men, to go out of the city and help them. If they did that, enemy would get surrounded from both sides and, unable to flee, would eventually succumb. But if they wouldn't come, well, it would be a massacre. On both sides.
After the initial preparations, Piruz ordered to attack, with every commander of respective parts of the army responding accordingly, initiating the attack. But something went wrong. The enemy spotted them much earlier then Piruz counted with. A rain of arrows fell on his army, while enemy soldiers were stuffing themselves into an armour, looking around for their weapons. But even if the enemy archers were already shooting, the charge went relatively well and most of the enemy soldiers didn't get the chance to even put their armour on before spear impaled them. Göktürks, normally using their cavalry to fight, were in big disadvantage. Their cavalrymen weren't as useful when on foot. And it was proved to be true when they fell one by one to Persian infantrymen, as if they were wheat.
But it went so well only in the beginning. After the initial chaos that was caused in the camp by the sudden attack, Göktürk soldiers started rallying around some man, who was organizing them into a proper defensive line. He was, presumably, a general of this army. And experienced one at that. He instantly drew the soldiers from the chaos that ensued after the attack and quickly rebuilt them into a proper defensive formation. When he was finished, it was no longer that chaotic crowd that didn't even fight back that stood before Piruz, now it was a proper army that posed a threat. And Piruz had to deal with this situation. Before him stood no less than around ten thousand men, while he still had around twelve thousand. Taking them head-on was pure suicide and so he did the only thing that he thought would be plausible, still waiting for the city's garrison to come and support them in the battle. After he relayed his strategy to his commanders, he was ready to begin realizing the plan. After a while, horn could be heard blowing. It was time.
The twelve-something thousand army started charging the Göktürks, who already had their spears and sabres ready for Persians. At first glance, one would say Piruz wanted to use their numbers and charge them head-on, overwhelming them. But he did not do such thing. When the army was in a certain distance from the enemy, it started stretching to sides, completely encircling the enemy from all sides but behind. As an eagle who stretches his wings, the Persians pushed the Göktürks into a crowded formation. Göktürks tried to flee through the gap Persians left them from behind. And some did, while other fought like a wild beast. But the battle was not yet won. Persians were stretched thin and every second, a breach on the line was more possible than before. Soldiers were dying on both sides, but Göktürks eventually started to gain upper hand over the young and elderly soldiers. Piruz of course saw that, and, being not only renowned commander, but also a skilled fighter, decided to go into the fray to support his soldiers. His personal guards were following him as he rode into battle which outcome hung on a thread. But then, he saw something that relieved his heart. He saw the city gates of Merv opening in front of him, soldiers emerging from them and ramming into the exposed back of the Göktürks. Now Piruz didn't have to hesitate – he grabbed his sabre firm and charged into the mass of bodies, joining the fight as regular soldier.
His personal guards were following him as he rode into battle which outcome hung on a thread. But then, he saw something that relieved his heart. He saw the city gates of Merv opening in front of him, soldiers emerging from them and ramming into the exposed back of the Göktürks. Now Piruz didn't have to hesitate – he grabbed his sabre firm and charged into the mass of bodies, joining the fight as regular soldier. The circle encircling the Göktürks turned into a controlled massacre. Göktürks, realizing they are surrounded from all sides tried to break the encirclement and retreat, but all in vain. Their every try ended in a one-sided massacre by the Persians. Some knelt and begged for mercy, some fought until their last breath and some played dead, only to be eventually stomped to death. It was a cruel battle, one that would come into history as the "Merv meat grinder."
Every Göktürk soldier was either killed or enslaved, and their general was executed in a horrific way. They put him into a trunk, where he was forced to drink milk and eat honey – ingredient, that made him to have diarrhea. Then, worms and rats, attracted by his excrements literally ate him alive from inside, while he couldn't do anything about it. It was a price to pay for assaulting Empire of Iranians. But Persian army didn't come unscathed from it either. Around four thousand were lost while another two thousand was hurt with about quarter of them not being able to ever fight again. But he won, Merv didn't fall and Göktürks were banished. And now, although not according to Piruz's plans, as he wanted to leisure around in Merv while waiting for the enemy to show themselves, he had to head back home. Back to his Shahanshah.