The Excubitors took part in the disastrous Pliska campaign in 811, when the Byzantine army was routed by Tsar Krum of Bulgaria; the Domestic of the Excubitors fell in the field along with the other senior Byzantine generals, including Emperor Nikephoros I himself (). The most prominent Domestic of the Excubitors of the period was Michael II the Amorian (), whose supporters overthrew Emperor Leo V the Armenian () and raised him to the throne. The regiment also fought at the battles of Boulgarophygon in 896 and Acheloos in 917, both heavy defeats against the Bulgarians. In the expedition against the Emirate of Crete in 949, the Byzantine force included a contingent of over 700 Excubitors. In 958, the Excubitors participated in the repulsion of a Magyar raid.