Justinian as World Conqueror
The Barberini Ivory, mid-sixth century

A larger image of Justinian as world conqueror. The Barberini Ivory, mid-sixth century.

Justinian as world conqueror (Barberini Ivory), left leaf of a diptych, mid-sixth century. Ivory, 1' 1 1/2" x 10 1/2". Louvre, Paris.
Source: Byzantium: The New Rome

Note the Germanic? soldiers at lower left and the Indians? at lower right.

The main panel is referenced on p.32, Byzantine Cavalryman c.900-1204 by Timothy Dawson (Author), Giuseppe Rava (Illustrator)
Although the rider's dress and equipment is characterized by antiquarian stylization, other evidence confirms that the horse furniture shown on the Barberini ivory is a good indication of how ornamental the best middle Byzantine era could be.

See also Byzantine soldiers on the Throne of Archbishop Maximian of Ravenna, Constantinople or Alexandria, 545-553AD
The Rabbula Gospels Evangelia characteribus Syriacis exarata Northern Syria, 586AD
6th-7th century Byzantines in the Ashburnham Pentateuch
Byzantine plates of the reign of Herakleios with biblical characters in Roman costume & armour, early 7th century
Other 6th Century Illustrations of Costume & Soldiers
Other Byzantine Illustrations of Costume & Soldiers