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"Cosmati" Floor Panel

11th century - 12th century
109 cm x 87 cm (42 15/16 in. x 34 1/4 in.)
porphyry and colored marbles on marble

On view


Mosaics in opus sectile (literally, “cut work”) are the rich cousins of the more common mosaics made of small cubes known as tesserae. The technique of opus sectile involves custom cutting colored stone into prescribed shapes to fashion figures or geometric designs, often inlaid on a marble substrate. It is thought to have been more expensive because of the materials – in this case, red and green porphyry – the intricate cutting required, and the supporting substrate. The medium, used in Roman times, was revived in the eleventh to thirteenth centuries in Italy and Greece.

Here a central rectangle is framed by discontinuous bands which curve around a series of circles and lozenges. Inlaid with patterns of squares and triangles, this mosaic resembles several in southern Italy, including a panel on the pulpit of the Cathedral of San Pietro in Fondi, south of Rome. This example likely formed part of a floor, given its substantial thickness and the rough surface of its back; another mosaic of similar design paved the choir of the Basilica di San Nicola in Bari, on the Adriatic coast. Given these comparisons, the Dumbarton Oaks opus sectile work is very likely of similar origin, made for the floor of a church in southern Italy.

The piece was given to Dumbarton Oaks in 1949 in memory of Joseph Brummer (1883–1947) by his widow and brother. Brummer had been a prominent art dealer in Paris and New York, with whom the Blisses had conducted business from the early years of their collecting.

- J. Hanson

The Dumbarton Oaks Collection, Harvard University (Washington, D.C., 1955), 147, no. 289.

Handbook of the Byzantine Collection (Washington, D.C., 1967), 103-4, no. 351.

G. Bühl, ed., Dumbarton Oaks: The Collections (Washington, D.C., 2008), 158, pl. p. 159.

R. de Leo, "A Conjecture on the Hausdorff Dimension of Attractors of Real Self-Projective Iterated Function Systems," Experimental Mathematics 24.3 (2015), esp. 276, fig. 3b.

Acquisition History
Gift of Ernest Brummer and Mrs. Joseph Brummer in memory of Joseph Brummer (dealer) to Dumbarton Oaks Research Library and Collection, Washington, DC, 1949.

Dumbarton Oaks Research Library and Collection, Byzantine Collection, Washington, DC.