Mieszko set out to spend his reign as a rebuilder and a restorer, working to restore the prosperity lost during the Plague. He began his rein by pouring thousands of gold coins out of Slavia's treasury into the construction of new walls and town facilities, creating new, modern housing to replace buildings torn down during the outbreak. Many old street plans in Pomerania today date from Mieszko's era.
The sole early foreign engagement Mieszko pressed was a war to bring part of Lettigalia into the empire. With much of Livonia willingly swearing fealty to the Slavic throne, Mieszko sent a small army to the gates of Selpils, ejecting a pagan ruler and installing a Christian one. These holdings in Lettigalia were divided by the scant holdings of the rightful Lithuanian King, who seethed at Mieszko's interference and refused to swear vassalage. Mieszko passed on the chance to war with him and simply let him cool his heels.
In 1135, Mieszko's wife died suddenly, evidently on the orders of his son-in-law, Prince Karlmann of the Holy Roman Empire - heir apparent to the rule of that entity. Mieszko himself was an honest man and no plotter, and no conclusive proof could be found on which to arrest Karlmann. Mieszko thus set out to chastise Karlmann another way: He broke ground on a new church in the far south of Poland, near the border of Carpathia, which he named the Church of Saint Felicitas, an early Christian martyr. Meanwhile, Mieszko acknowledged the birth of a bastard son, Milzas, before moving to betrothe himself to Elodie, the 15-year-old Duchess of Granada, not admiring her as a person or a beauty so much as an opportunity to birth a second son into a powerful ruling position in Andalusia - Elodie was the most powerful landholder in Andalusia at the time, with more land to her name than the King. While their eventual child was likely not Mieszko's - the two spent most of their reigns apart - Mieszko claimed the resulting daughter, whom he named Lidia.
Meanwhile, the opening of the new church at Zywiec was heralded as a splendid occasion - and a smirking Mieszko celebrated by proclaiming Prince Karlmann its first bishop. The protesting heir was promptly put under de facto house arrest in the church as Mieszko unilaterally made him a bishop and disqualified him from his birthright.
By 1138, his marriage to Elodie drew Mieszko into Andalusian politics. He joined Queen Glod of Sheffield Sweden that summer in declaring a quixotic war against King Sigismond the Black, who had been excommunicated. Slavic troops stormed the Andalusian capital at Murcia in 1139 but found Sigismond absent, and Mieszko ordered his men back onto the ships after hearing word of the monarch's real whereabouts: In Amiens, warring with the Duke of Picardy. Sigismond started south soon enough, though - but just as Mieszko disembarked his forces to meet him at Bordeaux, a papal legate arrived with word of the lifting of Sigismond's excommunication, and Mieszko returned home disappointed. He would sate himself by walking the Way of Saint James the next year.
Word came down in the winter of 1140 of the beatification of King Mscislaw, the man installed by Mieszko's mother to rule Hungary. Mieszko smiled patiently and returned to his life of meddling in Iberian politics and sleeping with everyone but his wife.
In 1142, with Slavia finalizing the capture of Finnmark from the Sami, a Crusade was called with eyes on Jerusalem. With the Abbasid Caliphate fracturing under the weight of its own decadence, Mieszko sent word that Slavia would carry the cross and the sword, but even with the fracturing of the Caliphate, the Islamic world was massing to meet Christendom's host. The refusal of West Francia to join the war left Christendom outmanned.
But the objective of the voyage quickly changed when Mayor Radomil of Odense, then the Grand Mayor of the Sealand Republic, urged the Crusaders to instead support the claim of Princess Anthe Radenos to the throne of the Eastern Roman Empire. She was the eldest daughter of the Emperor Methodios, a man who had spent the Empire into debt but whom Mieszko had no quarrel with.
Furious at the Crusaders, Mieszko withdrew his pledge to the Crusade, but he could not prevent his vassals from sailing off to Thrace to wage war in the name of the Cross. Finally, word of the inevitable came: The Crusaders breached the walls of Constantinople herself on October 24, 1145. Princess Anthe was killed in the course of the siege, and Pope Clement II himself retained control of the Queen of Cities, declaring Thrace a protectorate of the Papacy and the schism between Latin and Greek Christianity to be ended. Methodios himself was left clinging to a single barony in the Littoral, and the Eastern Roman Empire shattered into a thousand principalities.
Hoping at least to recover a shred of Christendom's dignity, Mieszko marched his men to war to drive the Khazars from Lesser Poland in 1147. That war ended within months when the elderly Khagan Menumarot simply brought his entire horde to bear, only for the armies of Pomerania to butcher about half of them. A series of quick sieges left this land, cut off by the Carpathians from the rest of Khazaria, under Slavic lordship.
Years of quiet followed in Slavia, interrupted mainly by the winged hussars traveling to Sweden to contribute to the slow stamping-out of the pretenders of Swithjod.
In 1155, word came down that an ambitious adventurer, Alain de Vasconia, was attempting to assemble an army of tens of thousands to invade Slavia. That lasted roughly until he died of a snakebite, and all returned to peace as Mieszko focused on improving his demesne keeps. The next year, another interloper met a dire end: The chronicler Jakusz of Streltza tells of the execution of "the Moorish lord, Salim," apparently one of several Barbary pirates captured attempting to sack Rastoku. It was also in this period that Mieszko's son-in-law, Borut, was placed on the throne of Lithuania by a palace coup, bringing that kingdom into the fold - but with Mieszko's seemingly-infertile daughter Malgorzata (described as "a giantess") unable to give him an heir, and with most of the duchies in that land answering to Mieszko rather than Borut, risk existed that the crown could pass out of Slavia again.
Most of Mieszko's affairs in this period seem to have been both personal and literal: He and Empress Elodie, ruling apart and usually separate, both apparently pursued numerous side affairs, ultimately growing to despise each other. Mieszko spent much of his time in those days overseeing construction of a new tower on the island of Rana, increasing the number of forts under his direct command. However, Elodie's death in 1159 due to a bad case of the flu left Mieszko's second legitimate son, five-year-old Udalrich, to rule in Granada. Ever eager to spread his seed, Mieszko quickly arranged a marriage to Tikshayka, the countess of the distant Kanin Peninsula - a rare appearance for the Nenets people in this part of history.
Of course, Mieszko promptly ruined that marriage, largely by cuckolding his son and siring another bastard upon his daughter-in-law Mala.
The sudden murder of Mieszko's son Udalrich in 1161 brought Granada under Mieszko's stewardship. With little desire to rule such a distant land himself, Mieszko granted his new holdings in Cordoba, Granada and Jaen to his bastard son Bartosz, then crowned him King of Andalusia and sent him on his way.
With Slavia's tributaries in Galicia-Volhynia at war to seize land on the Black Sea from the Khazars, Mieszko loaded his troops onto the ships and set sail. The war quickly resulted in the lands northwest of the peninsula, once steppeland, coming into the Galician realm.
Ultimately, a wave of camp fever sweeping Slavia claimed Mieszko when his court physician chose to treat him by cutting his eye out. An ailing Mieszko ordered the bishop executed, but it wasn't enough to save his own life, and he passed cursing the name of the churchman who maimed him, leaving behind children by at least four wives and countless more lovers, a stronger Slavia and a son on the throne of Andalusia.