With Manuel's resolve firm, the Bosporus Army continued its eastward advance under his command in early October, vowing to reclaim Paphlagonia, which had been lost to foreign hands for centuries.
At the same time, the crushing defeat of his eldest son, Ahmed, in Kandar territory also caught the attention of Sultan Murad II. While astonished by the formidable fighting power of Bosporus, he quickly allocated a small contingent of elite Anatolian troops to prevent the Crusaders from successfully combining forces, and ordered his son-in-law, Mahmud Pasha, to temporarily halt his suppression of the Aydın Restoration Army.
Furthermore, because Manuel, in this war, had also emulated his Brother-in-law by annexing many Genoese concession ports on the Asia Minor peninsula under the pretext of a holy war, causing Genoa to suffer commercial losses far exceeding expectations, the Genoese Council secretly allowed Ottoman forces to pass through the Dardanelles Strait, subtly providing considerable assistance to the Ottomans, who were ostensibly their enemies.
In addition, Murad II also began to publicize the truth that the holy fire disease was inextricably linked to Bosporus, attempting to divert domestic panic and reverse his deteriorating public reputation.
Facing an increasingly difficult situation, Manuel responded to challenges as they arose, fully demonstrating his ability and courage: after learning of the Ottoman deployment from spies and scouts, Caesar first ordered the entire army to accelerate its march in an orderly fashion, aiming to reach Bolu before Ahmed's and Mahmud Pasha's forces could converge, and defeat Ahmed's remnants once more; regarding the Genoese navy's actual defection, he directly ordered the navy to attempt to blockade the Sea of Marmara, while also assisting in transporting friendly forces such as the Knights Hospitaller to the eastern coast of the Aegean Sea, accelerating the collapse of local Ottoman defenses.
As for the "rumors" spread by Murad II, Caesar directly turned the tables, launching a propaganda offensive, claiming that this holy fire disease plague was entirely the Ottomans' own doing, a punishment from God for Murad II's blasphemy, and affectionately named it "Sultan Murad's Fire." He also had his literati extend this matter into one of the Ottomans' many sins and incorporate it into several letters, which were sent to the Pope, the Ecumenical Patriarch, the Catholicos of the Armenian Apostolic Church, and other patriarchs of major patriarchates, urging them to make a big deal out of it against the Ottomans. This successfully turned the matter into a bullet aimed at the Ottomans, causing the Christian populace under Ottoman rule to turn their hearts towards the Crusaders. By the end of that month, his actions even infuriated Murad II to the point of turning crimson and raging uncontrollably.
According to Serenus's later historical records, upon learning of Murad II's reaction at the time, Manuel, who had by then become Basileus, burst into laughter in the palace, mocking Murad's embarrassment and loss of composure from that year, and then uttered a cryptic phrase after a long pause,
"He's overheated, he's overheated, hahaha... You scoundrel Sultan, you'll have your day too..." Manuel, at the time, leaned on the table, feeling exceptionally joyful, even shedding tears of laughter.
However, these were matters for the future. Manuel, who still held the title of Bosphorus Caesar as his primary one, after entrusting the letter-writing task to his literati, immediately led his army westward without stopping after arranging for his vassal forces, until he directly clashed with Ahmed's forces, who were resting in Bolu, on October 10th.
In fact, ever since the Bosporus Army first defeated him, Prince Ahmed's subordinates had suggested withdrawing directly to Kocaeli, abandoning the relatively undefended Bolu region at that time, cutting losses in time, and awaiting reinforcements.
However, this subordinate's suggestion was quickly rejected by Ahmed himself and the Sultan behind him. Firstly, the arrogant prince firmly believed that he, having retreated to Bolu, was not without a fighting chance, and his father, out of the necessity to delay the enemy and maintain the front line, ultimately decided to have his eldest son continue to hold Bolu.
After all, the Romans seemed to still be seizing the remaining territories of the Kandar Beylik, and theoretically, it would take some time for them to arrive, so there should be ample time to gather reinforcements for Bolu.
But the Ottomans miscalculated. At this very moment, when Ahmed encountered the familiar yellow flag with a pure black double-headed eagle outside Bolu, cold sweat immediately poured down his face. Feeling incredibly panicked, he wanted to quickly discuss countermeasures with his adjutants beside him, but when he turned his head, he found only a few timid personal guards staring blankly, at a loss for words.
It was then that the prince remembered that during the defeat at Kastamonu, several of his adjutants were either killed in battle or went missing, and new adjutants and generals had not been promoted or transferred in time. Now, apart from having a temporary conscript army of less than ten thousand men, he was practically a commander without any staff.
After a moment of silence, Ahmed forced himself to gather confidence: he was not without advantages. His conscripts were all fanatical commoners who had lost loved ones due to Bosporus's atrocities and thus harbored deep hatred, turning to the army. In terms of fighting will, they seemed even comparable to the regularly trained Janissaries. If used in a city defense, they might not be without a fighting chance.
Of course, Ahmed was not one to be easily deceived by appearances; he was well aware of the difference between civilian conscripts and elite legionary soldiers. But after determining that there was no way out unless he abandoned the city, he could only muster his courage, persuading himself to rely on the city's defenses and the militia's fervor and desire for revenge to withstand the Bosporus Army's attack.
The prince, having made up his mind, immediately ordered the entire army to retreat into the city. But the Ottoman militia were only temporary conscripts, untrained in strict regular drills, and their varying skill levels made him anxious. As a result, half an hour later, when the Bosporus Tatar light cavalry arrived first, over a thousand Ottoman militiamen were still lingering by the city gate.
Seeing this situation, Ahmed had no choice but to bite the bullet and forcibly close the city gates, preventing the enemy from taking advantage to enter the city. Of course, by doing so, he also left those soldiers who had not managed to retreat outside the city, allowing them to be beheaded or captured by the enemy.
After the Bosporus cavalry joyfully accepted the Ottomans forced to remain outside the city as spoils of war, Caesar Manuel's main force, personally led by him, also arrived. When he saw that the Ottomans had indeed retreated into the city, a cold sneer appeared on his face.
"Get ready to catch a turtle in a jar."
What happened next was a very common situation in this era. Manuel directly ordered the Bosporus Army to set up their large and medium-sized cannons below the city, bombarding Bolu's walls day and night without cease. The Ottomans, who previously enjoyed using this tactic, now experienced it themselves, which could certainly be called a reversal of offensive and defensive positions.
However, the Ottoman defenders inside the city felt no joy at all about the enemy gaining the upper hand by employing their own favored tactic. Especially after the Bosporus Army cut off communication between the city and the outside world that same afternoon, the Turk soldiers and civilians inside the city looked utterly dejected: they could see that the city was not far from changing hands.
As if to confirm the defenders' thoughts, at the start of the siege, the Bosporus Army began to drive the Turks to serve as siege laborers, forcing them to carry pitchforks and wood to attack the city for them, which, while infuriating the defenders, also consumed a significant portion of their fresh forces. By the end of the first day of city defense, the high-morale militia that had given Ahmed confidence had suffered heavy and undeniable losses.
To make matters worse, when Ahmed inquired about the food reserves from the official in charge of the granaries within the city, this stout official, after a long silence, gave an extremely awkward reply, "Reporting, Your Highness, due to the recent prevalence of the holy fire disease, both farmers and herders have been severely affected, leading to most of Bolu's farmland and pastures being abandoned..."
"Get to the point!" Ahmed, who could probably guess what he was going to say, had no patience for his clichéd preamble and directly ordered the other party to tell him the most important part.
"There is not enough grain in the city to support the army for more than five days!" Yelled at by the prince, the granary official simply blurted out the truth.
Oh, no, it's over.
This was Ahmed's first thought.
Upon learning that Bolu had no foundation to continue holding out, his last shred of confidence in the defenders vanished. So, in the time that followed, Ahmed secretly began to prepare his escape route.
What happened next was simple: three days after the siege began, at midnight, the western wall of Bolu was breached. Ahmed, seeing that defending the city was hopeless, ultimately chose to secretly flee the city amidst the chaos, escorted by his Janissaries, escaping to Kocaeli. Three hours later, the Bosporus Army successfully captured Bolu, and this military town finally returned to Roman hands on the morning of October 7th.