[2] There were also special cubicularii/koubikoularioi for the empress (sometimes including female koubikoulariai), and the office was introduced into the Roman Church as well, probably under Pope Leo I.
[1] In Byzantium, they played a very important role, holding senior palace offices such as parakoimōmenos or the epi tēs trapezēs, but also served in posts in the central financial departments, as provincial administrators and sometimes even as generals.
[1] Gradually, in the 7th-8th centuries, the eunuchs of the imperial bedchamber proper (in Greek known as the [βασιλικὸς] κοιτῶν, [basilikos] koitōn) were separated from the other koubikoularioi and, distinguished as the koitōnitai (κοιτωνῖται), came under the authority of the parakoimōmenos.
[1] By the 9th century, aside from its general use denoting a eunuch palace servant, koubikoularios had also acquired a more technical meaning as a grade or dignity in the Byzantine palace hierarchy: according to the Klētorologion of 899, the rank of koubikoularios was the second-lowest among those reserved for the eunuchs, coming after the spatharokoubikoularios and before the nipsistiarios.
Again according to the Klētorologion, the distinctive insignia of the rank were a kamision (an over-cape similar to the paenula) edged with purple, and a paragaudion (tunic).