The restoration project of the so-called “Dungeons of Anemas” in 2006 shed light ona church structure at the basement level. The ruined structure is located on top ofthe “Dungeons of Anemas, part of the Blakhernai Palace, and in the northeast of the towers ofAnemas and Isaakios Komnenos. The purpose of this study is to introduce the newlydiscovered church ruins in context with the 12th and 13th century additions to the Palace ofBlakhernai and its environs.