Angel Garrison

Angel Garrison
Angels operate in garrisons, which are units or divisions in the Host of Heaven. Angels collectively contribute to the affairs and take part in activities assigned to their garrison. Every angelic group has its own leaders and supervisors that are separate from archangels.

So far, only Castiel's garrison has been mentioned.

Castiel's garrison
Castiel was a member of a garrison led by Anna Milton. Upon Anna's departure from Heaven, Castiel was given the title of leader in her stead. This particular garrison was assigned to watch over humanity for 2,000 years, without news or word from their superiors or God.

Four months after Dean Winchester went to Hell, this garrison was assigned the task of retrieving his soul. They launched a crusade and successfully retrieved Dean, with Castiel being the one to personally resurrect him. Castiel was later assigned to guide Dean through tasks delivered to him by Heaven.

Castiel, at Dean's insistence, would eventually abandon the Host of Heaven and side with the Winchesters in a bid to stop the Apocalypse. He presumably regained his former position in the garrison once they succeeded.

Following the outbreak of the Leviathans, Castiel mentions that his garrison was wiped out, or that some members had gone into hiding. He does not mention them again afterwards.

Known members While it is clear that Anna was the garrison's former captain, it is unknown what other rankings existed in the garrison. Uriel was a subordinate of Castiel up until the latter was deemed too attached to his charge (Dean), and was subsequently demoted. Uriel was also responsible for the death of seven garrison members, one of whom was shown at the beginning of On The Head Of A Pin.
 * Anna Milton (Formerly) (deceased)
 * Castiel
 * Uriel
 * Bartholomew
 * Seven unidentified angels (deceased)
 * Inias (presumably)
 * Balthazar (presumably) (deceased)