Hetaireia The Hetaireia or Hetaeria ( ) was a term for a corps of bodyguards during the Byzantine Empire . It means " the Company " , echoing the ancient Macedonian Companions . The most important such corps was the imperial " Hetaireia " ( βασιλική ἑταιρεία , " basilikē hetaireia " ) , composed chiefly of foreigners , which formed part of the Byzantine imperial guard alongside the " tagmata " in the 9th – 12th centuries . The term " hetaireia " was also applied to the smaller bodyguards of thematic military commanders ( " stratēgoi " ) , headed by a count ( κόμης τῆς ἑταιρείας , " komēs tēs hetaireias " ) , and from the 13th century on , it was employed in a generic sense for the armed retinues of magnates , bound by oath to their master . History and role of the imperial " Hetaireia " . The exact origin , role , and structure of the imperial " Hetaireia " are unclear . The term first appears in the early 9th century : narrative sources record its existence in 813 as a bodyguard for the Byzantine emperor on campaign . John B . Bury theorized that it was the evolution of the earlier " Foederati " , but this supposition was rejected by John Haldon . The " Hetaireia " of the middle Byzantine period was divided in several units : three or four according to the sources , distinguished by their epithets and each , at least originally , under is respective Hetaeriarch ( , " hetaireiarchēs " ) . The senior unit was the " Great " Hetaireia " " ( , " megalē hetaireia " ) , under the Great Hetaeriarch ( " megas hetaireiarchēs " ) , who ranked as the senior of the military officials known as " stratarchai " and was often referred to simply as " the Hetaeriarch " ( ) " par excellence " . It was a very important position in the late 9th and first half of the 10th centuries , as he was in charge of the Byzantine 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 Great Hetaeriarch 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 the " papias " of the palace . A " Middle " Hetaireia " " ( , " mesē hetaireia " ) is attested in sources , and the possible existence of a " Lesser " Hetaireia " " ( , " mikra hetaireia " ) is implied by the reference to Stylianos Zaoutzes as " mikros hetaireiarchēs " under Emperor Michael III ( r . 842 – 867 ) . Alternatively , the unit of the " mikros hetaireiarchēs " may be identical to the barbarian regiment composed of the two companies of the " Chazaroi " ( Χαζάροι , " Khazars " ) and the " Pharganoi " ( Φαργάνοι ) , which is called the " Third " Hetaireia " " ( , " tritē hetaireia " ) in the " Escorial Taktikon " of circa 975 . The historian Warren Treadgold estimates the total strength of the imperial " Hetaireia " in the early 10th century at 1 , 200 men . The bulk of the " Hetaireia " was apparently composed of foreigners ( " ethnikoi " ) , and contemporary accounts list Khazars , " Pharganoi " , " Tourkoi " ( i . e . Magyars ) , Franks and Arabs . The meaning of the term " Pharganoi " has been the subject of debate . It could denote their origin from the area of Central Asia around the Fergana Valley , or it could be a misspelling of " Pharangoi " , i . e . Varangians . Honorary posts in the " Hetaireia " , however , were prestigious appointments that could be purchased by native Byzantine officials , connected to an annual stipend ( " roga " ) paid by the imperial treasury to the holder . A post in the " Great " Hetaireia " " cost a minimum of 16 " litrai " of gold , a post in the " Middle " Hetaireia " " a minimum of ten , and in each of the " Chazaroi " or " Pharganoi " companies a minimum of seven . As the 10th century progressed , a tendency of amalgamation of the various units into a single command becomes evident , as the " Middle " Hetaireia " " seems to have been placed under the Great Hetaeriarch . The importance of the " Hetaireia " as a bodyguard corps declined thereafter , but the unit was one of the few regiments of the middle Byzantine army to survive into the Komnenian - era army , being attested well into the reign of Emperor Manuel I Komnenos ( r . 1143 – 1180 ) . By this time , however , its composition had changed : in the late 11th century , Nikephoros Bryennios the Younger reports that the " Hetaireia " was " customarily " made up of young Byzantine nobles . The post of " [ megas ] hetaireiarchēs " also survived , and , detached from its military duties , 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 . In the Palaiologan period , it was held by members of prominent noble families .