Trier Apocalypse
Carolingian, 8th-9th century, Folio 63, Stadtbib. Cod. 31

The 8th-9th century Trier Apocalypse includes some of the earliest representations of Carolingian warriors. It shows neither armour nor stirrups. (Cod. 31, f.63, Stadtbib., Trier)
Source: p.15, The Age of Charlemagne (Men-at-Arms 150) by D.Nicolle, A.McBride

The lower register is referenced on p.8, Carolingian Cavalryman AD 768-986 by D. Nicolle
‘Two confronted armies,’ in the 9th-century Trier Apocalypse. The complete lack of armour might reflect the fact that it was made in a relatively poor northwestern region of the Carolingian empire. (Stadtsbibliothek, Cod. 31, f. 63, Trier, Germany)

See also Carolingian Huntsmen, late 8th-early 9th Century, Nationalbibliothek Vienna
Carolingian Arms and Armor in the Ninth Century by Simon Coupland
8th Century Illustrations of Costume and Soldiers