As soon as Munadra received Weigandt's refusal to surrender, the Uthani Army was rallied, and marched just across the pass to surround and siege Teckitan. When they got there, they found the gate already barred to them, with militiamen loyal to the Sisathi movement patrolling the walls. An initial assault was attempted, but after light skirmishing the plan was abandoned and the army began to wait for a long siege. Merchants to Teckitan were turned away and sent to Uthan instead, and the river routes to and from Teckitan were blockaded for the time being. River craft patrolled up and down the river while soldiers were stationed at bridges as rudimentary checkpoints for boats and people crossing the river.
Traders and other visitors to Teckitan who decided to stay for a while in the city found themselves trapped in the siege and unable to get out. Anyone that tried to flee the city were treated Teckitan locals by the Sisathi militia and the Uthani army, almost always killed by either side.
Inside the city, the elite were already beginning to balk at the prospect of a prolonged siege. All their revenue from trading has suddenly stopped, and while they had a vast amount of material wealth at their disposal, gold and coins didn't do much in the face of a coming siege. One influential fur trader, Mirogniew Nowack attempted to negotiate with Weigandt for a potential deal with Uthan to lift the siege. Weigandt was so outraged by this proposal that he had Nowack hanged for treason. The sentiment of questioning this entire situation quickly soon spread to the populace. They didn't really have much to gain from the siege now, and that doubt has begun to spread throughout the masses. While the Sisathi movement retained a core support base that would follow Weigandt's words no matter what, if he lost public approval from the people of Teckitan then the siege would be over with him and his supporters in chains.
To combat this, he put Isidor as head of militia, and sent him to crack down on dissent in the city. To combat the inevitable "starving and dying" part that comes with sieges, he proposed simply just starting farms inside the city, to become their own little pocket of civilization functioning on their own. These initiatives were mildly successful, the most outspoken dissidents were hanged, but the interior farms failed due to a lack of space, and the tiny little gardens that did grow were hardly enough to feed the entire city. Many started to starve in the city, and lawlessness began to skyrocket. The militia were either unwilling to intervene to stop the looting, thieving and killing, or actively partook in such actions.
Weigandt and his inner circle didn't starve or suffer the ill effects of food storage at all. Instead they lived in the Claes manor and ate a lion's share of the Teckitan food stockpile, hosting elaborate feasts for the most prominent members of the Sisathi movement. After them, Sisathi militia got the next best share of food, and then the rest was distributed among the people.
In Uthan, the general attitude towards the resolution of the war was the same. Prominent trade barons and land owners were skittish to end the war quick, as the loss of Teckitan cut heavily into their profits, and the longer the siege went on, the more outside powers would seek to exploit the weakness of Uthan. Not only that, but a great amount of the Uthani army were peasants raised from their fields, and the longer they were diverted away, the longer their land would go unattended, which could only prove unfortunate in the long term. As a result, Munadra and the entirety of Uthan grew more desperate to end the conflict and destroy the Sisathi Movement without causing too much long-term damage to Teckitan.
After a few weeks, Weigandt realized that he too needed a major victory. The situation grew more and more dire for the movement the more time that went on. While the siege was merely a financial and political concern for Uthan, in Teckitan it was a mortal one. The food stock, without proper rationing, had lessened quite a bit, causing a worrying projection of food running out soon if actions weren't taken. The faith of the common people was also starting to wane, with people wondering more about what the movement was really all about. The initial wave of momentum had ceased, and now that people were starting to think about the whole movement, holes were being poked into the rhetoric of what Weigandt and his inner circle said and claimed. As such, he tasked Isidor with rallying the militia to score a major victory against the Uthani army to hopefully force them to a peace and preserve the fragile authority the Movement possessed in Teckitan.
The Sisathi militia wasn't very impressive as a fighting force. They were mostly made up of ideological zealots, with a large subset of people who just wanted to get in on being the dominant force in the city, with a good amount of the militia being former city guards or garrisoned Uthani soldiers. While the guards and former soldiers were the most elite of the militia, they made up a small amount of the total militia population. The group that made up most of the militia were untrained peasants or common people who had been given a makeshift weapon, a badge, and a helmet who were given relatively free reign over the city. They weren't very good at fighting other armed combatants, and it was expected that they would fail massively in any sort of military confrontation with the Uthani army, who outnumbered, outskilled, and outequipped them.
Uthani strategists and military commanders reckoned that in a head on confrontation with the militia, which was the only way the militia were going to be able to confront the besieging Uthani forces, the Sisathi militia would be crushed completely. The commander in charge of the besieging force was Cyrus Barzegari, a son of an Uthani trade baron who had been given the position to appease some of the political factions within the city-state. He was hardly qualified, having zero experience leading troops of any kind, and was generally overcautious when it came to combat, not wanting to lose face in front of the vast political array of Uthan that would undoubtedly jump on the barest chance to tear his reputation to shreds. The captains and on-the-ground commanders weren't much better, mostly either being trusted men of the political factions within the City-State, constantly fighting among themselves, while also not being the most strategically sound themselves.
When the date of the fateful confrontation between the militia and besieging army came, the Uthani Army wasn't prepared in the slightest. The couple months they had spent encamped had made them grow complacent, soldiers assured that the Sisathi militia wouldn't be stupid enough to come out of the walls and challenge them. When the militia did come out and charge at the first besiegers, they were caught completely off guard and retreated immediately, forsaking their defensive advantage and the possibility of breaching the city gates while they were still open. The militia also did little with their recently gained advantage, simply standing about and attempting to intimidate nearby soldiers, giving them ample time to create a response. This initial force, however, was meant as a diversionary force for the main counter siege army, who would slip out through the side gate and flank any attacking troops.
After about an hour of confusion, Cyrus finally got word of what was happening, and very haphazardly rallied a group of cavalry and foot soldiers to deal with the aggravating small band of militia by the gates of Teckitan. When Cyrus got there, he was immediately nervous and didn't know what to do in this situation. The captains and commanders were waiting for his input, and didn't know what to do. Cyrus himself was also hesitant to do anything, thinking it was an elaborate trap, and stayed away from the militia. The militiamen weren't leading the Uthani troops into a trap, they were simply highly intoxicated, having ingested opioids prior to sallying forth. This gave them a feeling of invincibility, which translated into their outer actions, and further dissuaded Cyrus from taking any action.
Instead of taking offensive action, Cyrus simply attempted to wait them out, with each passing hour he further convinced himself that the small band was actually an elaborate trap made to defeat him. The main militia force that was meant to flank the Uthani army had gotten stuck, most of their ranks had gone and got themselves drunk or otherwise unavailable, causing Isidor to simply wait for the next day to regroup. By nightfall, Cyrus's core troops had begun to grow tired of standing guard in the blazing sun for so long with no reprieve. Cyrus was also growing skittish, realizing that no victory would be just as bad as falling for an ambush. He consulted with his higher ranking commanders and decided to bring in the ranged units, an elite unit of archers. He didn't bring this unit in before mainly because he forgot about them in the panic, but also because the archers were the personal unit of Duke Oresto, a powerful noble who was opposed against Cyrus's father. Giving the unit any prestige would reflect well on Oresto, but getting them destroyed would enrage him to a point of open conflict against the Barzegari family.
In any case, the archers arrived after a half an hour and began to open up on the weary militia band, cutting them down easily. They were arrayed haphazardly, interspersed without rhyme or reason among the infantry, and clearly disorganized. The band died without any enemy fire response, and Cyrus declared a great victory over the thirty dead militia, and turned to leave with his weary troops back to their fortifications. However, at exactly this time, the militia counterattack began. A force of around four hundred disorganized but very motivated soldiers charged at the fatigued, off-guard and wrongly arrayed Uthani troops from a hidden-side exit. It was mostly made up of foot soldiers, though there was a few slingers and even cavalry with personally owned (or stolen) horses. The Uthani cavalry couldn't respond, seeing as their horses were on the verge of collapsing, along with their riders, and by the time the foot soldiers realized something was wrong, the militia were already upon them. The archers were hardly trained for close range combat, and sought to flee, causing chaos among the lines of troops.
By the time the rest of the Uthani army realized anything was going wrong, it was already too late. The militia had descended upon the soldiers like a swarm of rabid animals, fighting with little regard for their own or anyone else's safety. The militia archers and a few amateur mages had opened up on the Uthani army when they heard the sound of battle, further exacerbating the losses. Cyrus died when his horse threw him to the ground and trampled him. The fighting lasted for only about twenty-ish minutes before reinforcements were rallied and the militia preemptively retreated, but that was all it took. While the overall casualties were relatively low considering the total population of the rallied army, it was a humiliating defeat, and the losses took were much more than what should have been taken in an engagement with a bunch of disorganized militia. A large portion of the elite archers had died, and the core units of infantry and cavalry had taken massive losses.
The entire thing was a massive embarrassment for Uthan, causing an uproar among the upper class and causing bordering nations to view the City-State with increasing hunger once they heard the news. It was rumored that once Munadra had heard of the defeat he nearly killed the messenger in anger. If the full attention of the nobles wasn't on Teckitan before, it certainly was now. The besieging army burgeoned overnight, mercenaries and private armies deciding to enter the fray to end the Sisathi Movement and crush Teckitan before things really spiraled out of control.
Inside the city, Weigandt was on top of the world. He had basically proved his doubters wrong, solidified himself as the undisputed prophet of the sixth god and humiliated his enemies. The social pressure from the unhappy populace vanished overnight and the number of true believers skyrocketed as the shared mythos of this sixth god who would fix their problems grew and grew. Of course, basically all of the issues that preceded this skirmish outside of Teckitan had not gone away. Some of them had even grown stronger after, like the conviction of Uthan, but there was a large boost in morale and belief that the Sisathi Movement was going to succeed despite it all. The militia's power grew within the city, paraded around as war heroes and treated as such, looting and plundering in their own city. The food stores continued to empty at an unsustainable and irreplaceable rate, meaning that the Sisathi Movement's victory was proving to be short-lived.