The Mosaics of Hagia Sophia at Istanbul: The Portrait of the Emperor Alexander: A Report on Work Done by the Byzantine Institute in 1959 and 1960

Astronomical and Optical Principles in the Architecture of Hagia Sophia in Constantinople

“…Attention was paid especially to color contrasts in order to set apart individual motifs from either the background or one another. Characteristic, for instance, is that the ornamental borders in the aisles and in some of the original window decorations are regularly separated from the gold ground by a silver trim (Mango and Hawkins 1965, 127, 132–136; idem 1972, 8, 21; Underwood and Hawkins 1961, 201). In the sixth-century mosaics of the inner narthex the geometric motifs are outlined in red, once again enhancing the separation of the designs from their background.…”

“…Glass is generally more reflective than the other materials available at the time and was almost exclusively used for the sixth-century mosaics. Furthermore, metallic tesserae were often inclined at strategic places (Mango and Hawkins 1965, 127, 132–136; 1972, 8, 21; Underwood and Hawkins 1961, 201). For instance, in the west windows of the inner narthex, the gold tesserae in the northern window reveals are set in slight inclination from top to bottom, while the gold ground in the southern reveals is set in plane with the outline of the crosses (Whittemore 1933, 11–13).…”

The bricks of Hagia Sophia (Istanbul, Turkey): a new hypothesis to explain their compositional difference

“…Hagia Sophia, built in the 4th century AD, is one of the most important buildings in the world. Its constructive history is complex and widely discussed in the scientific literature (Emerson and Van Nice 1950;Underwood & Hawkins 1961;Van Nice 1965;Kinross 1974;Necipoglu 1992;Mainstone 2009;Erdik & Croci 2010;Cappa et al 2016; Barba et al 2018). It is possible to summarize its history in 4 major construction phases (Mainstone 2009).…”