Seljuk Battle Plate or Bowl, early 13th century.

A larger image of the Seljuk Battle Plate or Bowl, Kashan, Iran, early 13th century
A larger black and white detail of the Seljuk Battle Plate or Bowl, Kashan, Iran.
Kashan, Iran, early 13th century. Source: Freer Gallery F1943.3

Source: StudyBlue

Images of the outside of the Seljuk Battle Plate or Bowl, Kashan, Iran, early 13th century. Freer Gallery of Art F1943.3.

Referenced as figure 392 in The military technology of classical Islam by D Nicolle
392. Ceramic bowl, early 13th century AD, Iranian, Freer Gallery of Art no. 43-3, Washington (Elg).
p.174 Lamellar armour may also have been used in Byzantium in the pre-Islamic era39 (Figs. 90, 91 and 556) but its more widespread adoption after the 7th century clearly reflected Muslim military pressure40 (Figs. 212, 220A, 314, 630 and 637). A smaller but equally common kabadion lamellar cuirass was seen in Byzantium from the 10th century41 (Figs. 227, 242, 249, 314, 414 and 608). This could reflect the changing fashions of eastern Islam, where the lamellar kamaband may have been developed in the 10th century, or it could have been the Byzantine original that stimulated the adoption of this latter Iranian form of armour (Figs. 209, 241, 292, 294, 306, 347, 354, 376, 377, 385, 390, 392, 422, 446, 447 and 641).

39. Haldon, "Some Aspects of Byzantine Military Technology from the 6th to the 10th centuries," p. 20.
40. Ibid., pp. 25-26,29 and 46.
41. Ibid., p 36.

Reference: Renata Holod "The Freer Gallery's Siege Scene Plate" pp.195-219 in Ars Orientalis 42, 2013 or pdf

Seljuk infantry in Armies and Enemies of the Crusades 1096-1291 by Ian Heath, based on this Seljuk Battle bowl
Seljuk Illustrations of Costume & Soldiers