A second consideration in support of this identification is the statement made by Achmed Rifaat Effendi, that before the church became a mosque it was known by the name of its founder, 'Isakias.' For it is a matter of history that the church of S. Thekla was restored by the Emperor Isaac Comnenus[338] in the eleventh century. The association of his name with the building was therefore perfectly natural, if the building is indeed the old church of S. Thekla, otherwise it is difficult to account for that association. There is, however, one objection to this identification that must not be overlooked. According to Byzantine authorities, the church of S. Thekla stood in the palace of Blachernae ([Greek: entos tôn basileiôn; en tô palatiô tôn Blachernôn][339]). That palace occupied the heights above Aivan Serai, on which the quarter of Egri Kapou and the mosque of Aivas Effendi now stand, within the walls that enclose the western spur of the Sixth Hill. Toklou Ibrahim Dedé Mesjedi, however, does not stand within that enclosure, but immediately to the north of it, on the level tract that stretches from the foot of the Sixth Hill to the Golden Horn. If the reasons in favour of regarding the mosque as S. Thekla were less strong, this objection would, perhaps, be fatal. But the strip of land between the northern wall of the palace enclosure and the sea is so narrow, and was so closely connected with the life of the imperial residence, that a building on that tract might with pardonable inaccuracy be described, as 'in the palace.'[340]