Hetaireiarches

The  (ἑταιρειάρχης), sometimes anglicized as Hetaeriarch, was a high-ranking Byzantine officer, in command of the imperial bodyguard, the. In the 9th–10th centuries there appear to have been several, each for one of the subdivisions of the , but in later times only the senior of them, the  (μέγας ἑταιρειάρχης) or Great Hetaeriarch survived, eventually becoming simply a high court rank in the 12th–15th centuries.

History
The Imperial (βασιλική ἑταιρεία, ) was a bodyguard regiment of the Byzantine emperors in the 9th–11th centuries, originally recruited mainly from among foreigners. It is first mentioned in 812, as a bodyguard for the emperor on campaign, but its origin is obscure. The Imperial of the 9th–10th centuries was divided in several units: three or four according to the sources, distinguished by their epithets and each, at least originally, under is respective.

Thus the commanded the 'Great ' (μεγάλη ἑταιρεία, ). He was the senior of the military officials known as and as a result of his prominence was often referred to simply as 'the ' (ὁ ἑταιρειάρχης), without further qualification. It was a very important position in the late 9th and first half of the 10th centuries, as he was in charge of the emperor's security, and was entrusted with delicate assignments. It is telling that the future emperor Romanos Lekapenos held this post, and was succeeded by his son Christopher Lekapenos. According to the mid-10th century De Ceremoniis, written by Emperor Constantine VII Porphyrogennetos ((r. 913 – 959)), the and his unit are charged with the protection of the emperor's tent on campaign, and with the security of the imperial palace, in close association with another palace official, the.

A 'Middle ' (μέση ἑταιρεία, ) is attested in sources, but without its ; indeed, this unit appears to have been placed under the during the course of the 10th century. Conversely, a 'Lesser ' (μικρὰ ἑταιρεία, ) is not attested but implied by the reference to Stylianos Zaoutzes as holding the post of under Emperor Michael III ((r. 842 – 867)). Alternatively, the unit of the may be identical to the "barbarian" regiment composed of the two companies of the  (Χαζάροι, Khazars) and the, which is called the 'Third ' (τρίτη ἑταιρεία, ) in the Escorial Taktikon of c. 975.

In the 11th century, the post of became detached from its military duties, but remained an important court position: it was held by several influential palace eunuchs in the 11th century, and by second-rank nobles and junior relatives of the Byzantine imperial family, such as George Palaiologos, in the Komnenian period. Under Manuel I Komnenos ((r. 1143 – 1180)), the became responsible for arms production and conducted important diplomatic missions.

In the Palaiologan period, the was held by members of prominent noble families. In the Book of Offices of Pseudo-Kodinos, the is placed 25th in the palace hierarchy, between the  and the. In other Palaiologan-era lists, which include different ranks and offices and reflect the order of precedence at different times, he ranks as high as 23rd or as low as 27th. The spouse of a was a member of the women's court, and bore the feminine version of her husband's title:. Ordinary are also attested, at 63rd place, between the  and the. Other lists have them at 67th–69th place, below the, or even at 75th or 82nd place. Their chief function, according to Pseudo-Kodinos, was as ushers at receptions.

According to Pseudo-Kodinos, the court costume of the consisted of a plain silk  tunic and a staff  topped with a gilded knob and covered with alternating golden and blue braid. For ceremonies and festivities, he bore the domed hat, of yellow and golden silk and decorated with gold wire embroidery, and with a portrait of the emperor seated on a throne in front and another with the emperor on horseback on the rear. The ordinary was dressed in a long silk, a  covered in red velvet and topped by a small red tassel or a  hat of the  style, and a golden-topped staff covered with alternating yellow and blue braid.