flowers. There is a wealth of porphyry stone, too,
besprinkled with little bright stars....You may see
the bright green stone of Laconia and the glittering
marble with wavy veins found in the deep gullies
of the Iasian peaks, exhibiting slanting streaks of
blood-red and livid white; the pale yellow with
swirling red from the Lydian headland; the glitter-
ing crocus-like golden stone [of Libya];...glitter-
ing [Celtic] black [with] here and there an abun-
dance of milk; the pale onyx with glint of precious
metal; and [Thessalian marble] in parts vivid green
not unlike emerald....It has spots resembling
snow next to flashes of black so that in one stone
various beauties mingle.^1The feature that distinguishes Hagia Sophia from equally lavish
Roman buildings such as the Pantheon (FIG. 10-51) is the special
mystical quality of the light that floods the interior (FIG. 12-4). The
soaring canopy-like dome that dominates the inside as well as the
outside of the church rides on a halo of light from windows in
the dome’s base. Visitors to Hagia Sophia from Justinian’s time to to-
day have been struck by the light within the church and its effect on
the human spirit. The 40 windows at the base of the dome create the
illusion that the dome is resting on the light that pours through
them. Procopius, who wrote at the emperor’s request a treatise on
his ambitious building program, observed that the dome looked as if
it were suspended by “a golden chain from Heaven.” Said he: “You
might say that the space is not illuminated by the sun from the out-
side, but that the radiance is generated within, so great an abun-
dance of light bathes this shrine all around.”^2
Paul the Silentiary compared the dome to “the firmament which
rests on air” and described the vaulting as covered with “gilded tesserae
from which a glittering stream of golden rays pours abundantly and
strikes men’s eyes with irresistible force. It is as if one were gazing at the
midday sun in spring.”^3 Thus, Hagia Sophia has a vastness of space shot
through with light, and a central dome that appears to be supported by
the light it admits. Light is the mystical element—light that glitters in
the mosaics, shines forth from the marble-clad walls and floors, and
pervades and defines spaces that, in themselves, seem to escape defini-
tion. Light seems to dissolve material substance and transform it into
an abstract spiritual vision. Pseudo-Dionysius, perhaps the most influ-
ential mystic philosopher of the age, wrote in The Divine Names: “Light
comes from the Good and... light is the visual image of God.”^4
PENDENTIVESTo achieve this illusion of a floating “dome of
Heaven,” Justinian’s architects used pendentives (see “Pendentives and
Squinches,” page 315) to transfer the weight from the great dome to
the piers beneath, rather than to the walls. With pendentives (FIG.
12-5,left), not only could the space beneath the dome be unob-
structed but scores of windows also could puncture the walls them-
selves. Pendentives created the impression of a dome suspended
above, not held up by, walls. Experts today can explain the technical
virtuosity of Anthemius and Isidorus, but it remained a mystery to
their contemporaries. Procopius communicated the sense of won-
derment experienced by those who entered Justinian’s great church:
“No matter how much they concentrate their attention on this and
that, and examine everything with contracted eyebrows, they are un-
able to understand the craftsmanship and always depart from there
amazed by the perplexing spectacle.”^5
By placing a hemispherical dome on a square base instead of on
a circular base, as in the Pantheon, Anthemius and Isidorus suc-
ceeded in fusing two previously independent and seemingly mutu-
ally exclusive architectural traditions: the vertically oriented central-
plan building and the longitudinally oriented basilica. Hagia Sophia
is, in essence, a domed basilica (FIG. 12-3)—a uniquely successful
conclusion to several centuries of experimentation in Christian
church architecture. However, the thrusts of the pendentive con-
struction at Hagia Sophia made external buttresses necessary, as well
as huge internal northern and southern wall piers and eastern and
western half-domes (FIG. 12-4). The semidomes’ thrusts descend, in
turn, into still smaller half-domes surmounting columned exedrae
that give a curving flow to the design.314 Chapter 12 BYZANTIUM12-4Anthemius of Trallesand Isidorus
of Miletus,interior of Hagia Sophia (looking
southwest), Constantinople (Istanbul), Turkey,
532–537.
Pendentive construction made possible Hagia Sophia’s
lofty dome, which seems to ride on a halo of light.
A contemporary said the dome seemed to be sus-
pended by “a golden chain from Heaven.”