The Theotokos Kosmosoteira () is a Greek Orthodox monastery in Feres, Evros Prefecture, Greece. It was built around 1152 by the sebastokrator Isaac Komnenos, a son of the Byzantine emperor Alexios I Komnenos. The monastery became the core of the settlement of Feres, but is last attested in the mid-14th century. By the 15th-century, under the Ottoman Empire, the complex was a mosque; it again became a church in 1940. History Isaac began construction of the monastery, which was meant as his residence and final resting place, sometime before 1152. The site, known as Bera (, from a Slavic word for "marsh") was then uninhabited and densely overgrown location, but the main church (katholikon) was apparently erected on the remains of an earlier, possibly Roman-era, building. Isaac drafted its regulations (typikon) himself, with those of the Theotokos Euergetis Monastery at Constantinople as his model. Isaac stipulated it as a cenobitic monastery for 74 monks, of whom 50 choir brothers (free from menial labour and dedicated to the church services), all over 30 years old. Eunuchs were explicitly barred. The monastery was under the local metropolitan bishopric of Trajanopolis. The complex was surrounded by a double fortified wall, with fortified gates and towers, of which only the interior can be traced: it apparently had a roughly hexagonal form, with towers at each corner, of which three survive in relatively good shape. It included a cistern, mill, and library, as well as a 36-bed hospital for the elderly and a bathhouse open to use by the local villagers. To support its operation and ensure its financial independence, Isaac endowed the monastery with extensive estates across Thrace. Isaac also built two bridges over the Evros river in the area, for whose upkeep the monastery's abbot was made responsible. In winter 1183/84, Emperor Andronikos I Komnenos (), Isaac's son, visited the monastery where his father was buried. In April 1195, the deposed emperor Isaac II Angelos () was blinded there. In the partition of the Byzantine Empire after the Fourth Crusade, Bera fell to the individual Crusaders' share, and came under the control of Geoffrey of Villehardouin, who sent his nephew Anseau de Courcelles to take over the monastery and his other fiefs in the region. In the 1300s, an abbot by the name of John is attested. Gradually, the monastery became the core of a larger settlement, which due to the endemic wars