Byzantium thus enjoyed a period of peace except in the West, where the Byzantine government proved unable to halt the ongoing Muslim conquest of Sicily. Modica fell in 845, but although Constantinople used the relative quiet in the East to send reinforcements to the island, these were heavily defeated at Butera, where the Byzantines lost about 10,000 men. In the wake of this disaster, Leontini in 846 and then Ragusa in 848 fell to the Muslims, while an attempt by the Byzantine fleet to land troops near Palermo in winter 847/848 failed. Over the next few years, the Muslims raided the Byzantine territories on the eastern half of the island unopposed, capturing several minor fortresses and securing ransom and prisoners from others. Only fragmentary evidence survives concerning Theoktistos' domestic policies. The "Oxford Dictionary of Byzantium" credits him with "continuing the sound fiscal policies of Theophilos", leading to the accumulation of considerable monetary reserves in the imperial treasury, to the amount of 19,000 pounds of gold and 30,000 pounds of silver by 856. He also promoted the career of Constantine-Cyril, whom he first met , helping him to acquire a good education and later to find a post as "chartophylax" in the patriarchal library, after Constantine rejected an offer of becoming a provincial "strategos". Theoktistos' sponsorship of men like Constantine and Leo the Mathematician contributed to the revival of secular learning in Byzantium. Theoktistos was also engaged in building activity, erecting new structures in the Apsis near the Great Palace of Constantinople, installing a new iron door in the Chalke Gate, as well as sponsoring unspecified buildings in the Thracian suburbs of Constantinople, notably Selymbria. In 855, Michael III turned fifteen and thus came nominally of age. His mother and Theoktistos both underestimated the young emperor's desire to free himself from their custodianship, and antagonized him further when they arranged a bride show and selected Eudokia Dekapolitissa as his bride, disregarding Michael's attachment to his mistress, Eudokia Ingerina. Theodora's brother Bardas was able to use Michael's resentment for the high-handed manner in which he was treated and began to turn him against the regency. With Michael's backing, Bardas was allowed to return to the capital, and on 20 November 855, Theoktistos was murdered.