The Monastery of the Savior Christ Sosander of Asia Minor was an Asia Minor Byzantine monastery near Nymphaeum in Ionia and Magnesia during Sipylos . The monastery was built in honor of the Gorgoepiko Virgo during the life of Vatatzis, the Savior Christ according to Grigoras. It was founded by the emperor John III Duke Vatatzis . The emperors John III Batatzis (as the founder of the monastery) and Theodoros II Laskaris were buried in the Monastery of Sosandron. The events that led to the assassination of the Byzantine official George Mouzalonos and his brothers in 1258 also unfolded in it .