According to Salzenberg, the palace belongs to the earlier half of the ninth century, and was the work of the Emperor Theophilus.[441] But the name of the building is in favour of the view that we have here an erection of the Emperor Constantine Porphyrogenitus, and consequently a monument of the Art of the tenth century. Constantine Porphyrogenitus was noted for the number of palaces he erected.[442] [Illustration: The Palace of the Porphyrogenitus (View of Interior).] At the north-western end of the court stood another residence, the western façade of which, pierced by spacious windows, still surmounts the outer wall of the court. Over the second window (from the south) was inscribed the monogram of the legend on the arms of the Palæologi;[443] Βασιλεὺς Βασιλέων Βασιλεύων Βασιλεύουσι. Dr. Paspates[444] regarded this building as the Monastery of the Seven Orders of the Angels, mentioned by Cantacuzene;[445] but that monastery, and the gate named after it, were at Thessalonica, and not at Constantinople. The building formed part of the Palace of the Porphyrogenitus. Bullialdus, the annotator of Ducas,[446] speaking of the palace, says that the double-headed eagle of the Palæologi was to be seen on the lintel of one of the doors; that the capitals of the pillars in the building bore the lilies of France; and that several armorial shields were found there with the monogram— [Illustration: Monogram.] These ornaments may be indications of repairs made by different occupants of the palace.[447] Footnote 428: Critobolus, i. c. 27; Cantacuzene, i. p. 305. Footnote 429: See below, Chap. XIX. Footnote 430: Tekfour Serai means Palace of the Sovereign, from a Persian word signifying Wearer of the Crown, Crowned Head. Leunclavius (_Pandectes Historiæ Turcicæ_, s. 56, Migne, vol. clix.) says that the Turks, in his day, styled the emperor, Tegguires. The derivation of Tekfour from the Greek τοῦ κυρίου is untenable. Footnote 431: See below, p. 173. Footnote 432: I. c. 27. Ἀπὸ τῆς Ξυλίνης πύλης ἀνιόντι μέχρι τῶν βασιλείων τοῦ Πορφυρογεννήτου, καὶ φθάνοντι μέχρι τῆς λεγομένης πύλης τοῦ Χαρισοῦ. Footnote 433: Cantacuzene, i. p. 305. Footnote 434: Nicephorus Greg., ix. p. 420. Footnote 435: See below, p. 127. Footnote 436: Cantacuzene, iii. p. 607. Footnote 437: Cantacuzene, iii. pp. 611, 612; Nicephorus Greg., xv. pp. 774-779. Footnote 438: Cantacuzene, iv. pp. 290, 291. Footnote 439: Tafferner (see below, p. 113, reference 5) speaks of a propylæum supported by ten fine columns as the entrance to the court of the palace from the city. Footnote 440: Cantacuzene, iii. p. 138, Τὴν τοῦ Πορφυρογεννήτου προσαγορευομένην πυλίδα. Footnote 441: From _Broken Bits of Byzantium_. (By kind permission of Mrs. Walker.) Footnote 442: Salzenberg, _Altchristliche Bandenkmäler von Constantinopel_, p. 125. Footnote 443: