|What makes you think I can do that?|
This page contains conjecture or inductive logic about a subject that is not explicitly mentioned or explained in the canon.
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 the archangels.
So far, only 2 garrisons were mentioned.
Castiel was a member of a garrison led by Anna Milton. Upon Anna's fall from Heaven, Castiel was given the position of leader instead. 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 with 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 then ordered to guide Dean through tasks delivered to him from Heaven.
Unfortunately, Castiel's growing attachment to Dean led to his demotion and Uriel's promotion. Later on, at Dean's insistence, Castiel would abandon the Host of Heaven and side with the Winchesters in a bid to stop the Apocalypse.
Following the outbreak of the Leviathans, Hester was said to have taken charge of the garrison, only to lose this position when Meg killed her to protect Castiel. Castiel himself mentioned sometime later that his entire garrison had been wiped out, or that some of the members had gone into hiding. He has not mentioned them again since.
- Anna Milton (deceased)
- Uriel (deceased)
- Seven unidentified angels (deceased)
- Inias (unknown)
- Hester (deceased)
- Balthazar (deceased)
While it is clear that Anna was the garrison's former captain, it is unknown what other rankings existed in the garrison. Uriel was under Castiel's command 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.
Before joining the Anna Milton's Garrison, Castiel was serving under Ishim along with Benjamin, Mirabel and two unnamed other angels. Their exact mission was unknown but in 1901, they arrived on Earth in order to eliminate a Nephilim, which was a lie made up by their leader in order to get revenge on Lily Sunder. Believing Ishim's lies, they killed the Seraphim Akobel and Ishim murdered Lily's human daughter May, the supposed Nephilim.
At some point, Castiel left Ishim's Garrison and joined Anna's Garrison where he will be the successor of Anna as the Garrison's leader.
Following the Fall of the Angels, Lily, wielding Enochian magic, began hunting down the members of the Garrison for revenge. Lily was able to kill the two unnamed angels and Benjamin who sent out a distress call to the surviving three members of the Garrison before his death. Lily killed Mirabel, but was prevented from killing Ishim or Castiel by the Winchesters. After learning of the truth from Lily, the Winchesters aided her in a fight with Ishim which ended when Castiel, having learned the truth about Ishim's actions, killed his former commander to save Lily. While Lily wasn't sure if she could forgive Castiel, he apologized for his own actions promised to accept the consequences if Lily chose to come back after him for revenge.