and other fortresses on the Adriatic by the end of February 1258. Konstantin Tih of Bulgaria repudiated his first wife and sued for the hand of Theodore's eldest daughter, Irene. He knew that his marriage to Irene, who was Tzar Ivan Asen II's granddaughter, could strengthen his claim to rule. Theodore wanted to confirm his peace treaty with Bulgaria and accepted Konstantin Tih's offer. Irene went to Bulgaria to marry Konstantin Tih. Theodore rarely left his palace at Magnesia during the last months of his life. He was convinced that sorcery caused his illness and accused his courtiers of casting spells on him, sending many of them for trial. Michael Palaiologos's sister, Maria-Martha, was the most famous victim of Theodore's paranoia. Theodore had forced her daughter, Theodora, to marry the elderly Basil Kaballarios, but the marriage was never consummated. After Kaballarios had attributed his impotence to his mother-in-law's spells, Theodore had her put into a sack filled with cats that tore her flesh. She was only released because Theodore suddenly panicked, fearing her spells. Also fearing her brother's revenge, Theodore had Michael Palaiologos imprisoned on charges of poisoning, but soon set him free. Theodore named his seven-year-old son, John, as his sole heir, appointing George Mouzalon regent until John came of age. He became a monk, but he kept his baptismal name. He summarized his sins in a treatise and asked the patriarchal synod to grant him absolution. He died in the imperial palace at Magnesia on 16 August 1258. He was buried next to his father in the Sosandra monastery on Mount Sipylus. His grave and the monastery were destroyed after the Turkish conquest of the region in the 14th century. The aristocrats had taken an oath of loyalty to Mouzalon at Theodore's deathbed, but they soon began conspiring against him. In ten days, Mouzalon was murdered, and Michael Palaiologos assumed the regency for the child-emperor, John IV Laskaris. Palaiologos convinced the aristocrats that an empire ruled by a boy could not resist enemy attacks, and he was proclaimed co-emperor as Michael VIII before the end of the year. When Michael VIII and John IV were crowned together early in 1259, the Patriarch put the crown first on Michael VIII's head. After concluding an agreement with Genoa against the Latin Empire, he dispatched Alexios Strategopoulos to spy on the defences of Constantinople. Taking advantage of the absence of the