After being mentioned in a letter by Justinian II () to Pope John V in 687, the Excubitors as a corps disappear from the historical sources until they re-emerge, under a new commander, the Domestic of the Excubitors (, "domestikos tōn exkoubitōn") and in a new capacity, as one of the imperial "tagmata", the elite professional central army established by Constantine V (). As one of the "tagmata", the Excubitors were no longer a palace guard, but a unit actively engaged in military campaigns. At the same time, the "tagmata" represented a counterbalance to the thematic armies of the provinces and constituted a powerful tool in implementing the iconoclastic policies pursued by Constantine V. Their original role as palace guardians was taken over by another, newly created "tagma", that of the "Vigla".