22] now Fetiyeh Jamissi; secondly, on the ground of the
tradition current in the Greek community on that point. The latter
reason is in this case particularly strong, seeing the church of the
Pammakaristos was the patriarchal cathedral almost immediately after the
Turkish conquest, and retained that honour until 1591.[323] The highest
Greek ecclesiastical authorities were therefore in a position to be
thoroughly acquainted with the dedication of a church in their close
vicinity. In 1578 the protonotarius of the patriarch showed Gerlach the
site of the Trullus close to Achmed Pasha Mesjedi.[324]

The church is mentioned in history only by Phrantzes,[325] who informs
us that when the Patriarch Gennadius transferred the patriarchal seat
to the monastery and church of the Pammakaristos, certain nuns
previously accommodated in that House were removed to the neighbouring
monastery of S. John Baptist in Trullo. Phrantzes explains the
designation of the church, 'in Trullo,' as derived from a palace named
Trullus which once stood in the vicinity to the north of the
Pammakaristos. It was the palace, adds the historian,[326] in which the
Council of Constantinople, known as the Concilium Quinisextum ([Greek:
Penthekte]), or the second Concilium Trullanum, assembled in 692, in the
reign of Justinian II. But the palace Trullus, in which the first
Concilium Trullanum met in 680, was one of the group of buildings
forming the Great Palace[327] beside the Hippodrome, and there the
second Concilium Trullanum also held its meetings.[328] Phrantzes is
therefore mistaken in associating the Council of 692 with a palace in
the vicinity of the Pammakaristos and Achmed Pasha Mesjedi. But his
mistake on that particular point does not preclude the existence of a
palace named Trullus in the neighbourhood of the Pammakaristos. In fact,
the existence of such a palace in that district is the only possible
explanation of the attachment of the style 'in Trullo' to a church on
the site of Achmed Pasha Mesjedi. Nor is it strange to find a name
pertaining primarily to a building in the Great Palace transferred to a
similar building situated elsewhere. The imperial residence at the
Hebdomon, for example, was named Magnaura after one of the halls in the
Great Palace.[329] There was an Oaton or Trullus in the palace of
Blachernae,[330] and in the palace at Nicaea.[331] Consequently, a
palace known as the Oaton or the Trullus might also be situated near the
Pa