Marcellus (comes excubitorum)

Marcellus (Greek: Μάρκελλος) was an East Roman (Byzantine) judicial official, one of the closest aides of the Byzantine emperor Justinian I (r. 527–565) and commander of the imperial bodyguard of the excubitores in circa 541–552.

Nothing is known of his early life and career, but he was evidently an experienced judge, for on April 8, 539 Emperor Justinian appointed him as one of the four senior judges (iudices pedanei). It is possible that he was one of the comites consistoriani, since he is referred to as comes in 540. In the Novel concerning his appointment, he is recorded by Emperor Justinian as being a close associate and "famous for his concern for justice", while the historian Procopius of Caesarea describes him as very austere, incorruptible, and a forbidding personality, with a profound concern for justice and truth.

By early 541, Marcellus had been appointed to the very influential post of comes excubitorum, head of the imperial and palace guard.

In May 541, he was involved in a plot by the Empress Theodora and her close friend Antonina, directed against Emperor Justinian's powerful but widely disliked praetorian prefect, John the Cappadocian. John had grown exceedingly powerful, surrounding himself with thousands of armed retainers. Theodora resented his influence over Emperor Justinian, while John hated the popular general Belisarius, Antonina's husband.

Between them, Theodora and Antonina contrived a plan to make the prefect confess to treasonous intentions: using his daughter as an intermediary, Antonina confided that Belisarius was considering a coup, and asked for John's assistance. A meeting was arranged at the palace of Rufinianae near Chalcedon, where Marcellus, along with the eunuch praepositus sacri cubiculi Narses and many soldiers were in attendance to witness the events. Marcellus and Narses were ordered by Theodora to kill John if he spoke out in favor of treason. In the ensuing scuffle, however, John escaped and fled to a church, while Marcellus was wounded by one of John's guards. John was removed from office immediately after and was banished to Cyzicus.

...
Wikipedia