However, when Theodosius II built his formidable land walls in 413–414, the church became incorporated within the city's defences, but retained the name Chora. The name must have carried symbolic meaning, as the mosaics in the narthex describe Christ as the Land of the Living, hē Chōra tōn zōntōn) and Mary, the Mother of Jesus, as the Container of the Uncontainable ,