This is all Castiel's minor relationships he encounters through his life and time on Earth. Though by Season 6, Castiel has severed most of his relationships, presumbly as a result of his quest to stop the civil war raging in Heaven. Now that he has become God for a short time, it is not known if Castiel's former relationships have been damaged beyond repair due to his actions or if there's any hope of fixing them.
Balthazar did help Castiel, and aided him in the civil war in heaven. Balthazar then was under Castiel's command.
After learning that Balthazar betrayed him by giving away his location to Sam and Dean, Castiel, knowing that his former friend had become a loose end, lured Balthazar to a place under the guise of talks before sneaking up behind the other angel and stabbing him with an angel blade. This resulted in Balthazar's death and it's presumed that Castiel felt some guilt over killing his former friend.
Uriel went rogue and tried to convert Castiel to his own plan of helping Lucifer destory mankind. Castiel refused, and the two sworn rivals then engaged in a bitter fight to the death. Just when it looked like Castiel was about to be defeated and killed, former angel Anna Milton came up and stabbed Uriel, killing him and saving Castiel's life.Purgatory. Castiel needed the souls to win the war in heaven, so he secretly began working with Crowley. He even went so far as faking Crowley's death.
Castiel did help collect creatures for Crowley to experiment upon. Eventually, Castiel betrayed Crowley and opened the door to Purgatory himself. Thus, their working relationship ended.
Castiel later declared himself the new God, and killed Raphael before deciding to spare Crowley, saying that he had plans for him. Those plans were that Castiel would control the flow of souls going into hell, and that Crowley could continue to rule there.
When Crowley encountered the now-insane Castiel, he was furious to find him still alive, and also angry that the Winchesters were harboring him. However, Crowley left him alone for the time being, stating that it would be no fun to kill him in his crazy state. He asked Sam and Dean to call him when Castiel regained his sanity so they could fight.
At this time, Crowley respected Castiel's wishes for him not to harm Meg. This was probably due to the fact they had a common enemy to fight. The Winchesters needed Castiel, and Castiel was fond of Meg.
When Castiel returned from Purgatory, he faced off with Crowley even in his weakened state. Castiel tried to smite Crowley, terrifying the King of Hell into fleeing. Castiel managed to damage Crowley's current plans by breaking The Word of God in half, causing Crowley to only get away with one half.
Crowley later captures Castiel, and shoots him in the gut with a gun loaded with bullets made from a melted-down Angel Blade, severely injuring him. Crowley had correctly deduced that Castiel had the angel tablet inside of him, and painfully removes it through the hole his bullet made.
In his weakened state, Castiel manages to escape when Crowley leaves him with a single guard. Later, desperate to save Sam from Gadreel, Castiel works with Crowley to allow them to communicate with Sam, and have him force Gadreel out (having gotten the idea from Crowley's torture of Samandriel). As part of the efforts, Castiel has to burn off Sam's anti-possession tattoo so Crowley can possess him. ("Cast that punk-ass, holy roller out!")
The plan to use Crowley to save Sam succeeds, and Sam expels Gadreel. Afterward, following Dean's lead, Castiel lets Crowley go as part of their deal.
Castiel has never met God, but follows his orders out of faith. He was obedient until Dean began putting doubts in his head as to who was really giving the angels their orders. Castiel had always followed orders to the best of his abilities, believing them to be passed down to him from God.
Castiel eventually rebels against heaven and helps Dean. In Season 5, he begins to look for God in order to stop Lucifer, using Dean's Amulet, but is severely disenchanted when being led to believe God simply doesn't care about the state of things anymore.
Unlike any angel, Castiel has been brought back to life many times, and he assumes that God himself has revived him. As an apparent reward for his role in averting The Apocalypse, God (or someone else), increases Castiel's power and upgrades him with more power. Later on, Castiel asks for God's help, but God doesn't respond.
Following this failure to get God's notice, and other, previous failures, Castiel takes many souls into himself (including the Leviathans), and declares himself to be the new God. Power drunk but well meaning, he quite possibly becomes the greatest threat that the world has ever known.
God (apparently) resurrects Castiel after the angel dies due to being possessed by the Leviathans. Although God brings him back with his powers intact, Castiel has no memories for some reason. It becomes apparent later that his identity and memories are just buried, and he is able to regain them by vanquishing demons.
Castiel now believes that this and other resurrections are a punishment that gets worse each time, and that if he dies again, God will continue to bring him back for more punishment.Anna's relationship goes back thousands of years. They served together in heaven in the same garrison. They were probaly close, as Castiel states "we have history together".
After Anna falls, Castiel and Uriel are the ones who are asigned to bring her in. Castiel says he is sorry, but he will kill her because orders are orders. However, Anna gains her grace back and escapes.
The next time Castiel sees her, he tells her he has orders to destroy her, but she knows that he won't. She calls him by his nickname, Cas, and questions whether what he is doing is right. She wants to work together with him, but he becomes angry and states that he is nothing like her, and tells her to leave.
Later, Castiel calls her back and asks her for help on what he should do. She tells him it is time for him to start thinking for himself.
Anna saves Castiel's life during the fight with Uriel, and kills Uriel. When Anna confronts him about letting Sam out of Bobby Singer's panic room, he betrays her trust and has two angels take her away.
Anna eventually escapes heaven, but has been brainwashed and reduced to factory settings. She is angry at Castiel for turning her in. She wants to kill Sam, but Castiel tells her that if she tries he will kill her despite what they have been through together. This is the last time they see each other before Anna is killed by Michael.
Ever since Raphael killed Castiel in Lucifer Rising, the two have been enemies. Before Castiel rebelled, it is believed Castiel probably respected Raphael due to rank. Although after being killed, Castiel returns and confronts Raphael on where God is. Their hatred for one another escalates when Raphael wants to restart the Apocalypse. Castiel refuses to let this happen and with a deal with Crowley, he starts a civil war in Heaven. After absorbing the souls of Purgatory, Castiel kills Raphael in a similar matter himself was killed in.
When Lucifer rebelled against heaven, Castiel (a newly created angel at the time) remembers being terrified by the raging archangel. Despite this, Lucifer does know of Castiel and sees him as a brother. When they meet again, after Castiel rebelled against Heaven, he is being trapped in a circle of Holy Oil by Lucifer who tries to persuade Castiel to work with him by listing things they have got in "common". He also makes it appear as if he is the victim and that his only mistake is loving god too much. Nevertheless Castiel does not fall for that so he leaves Castiel in the circle while Meg stays with him to watch out that he does not manage to free himself.
Castiel and BartholomewEdit
In Heaven, Castiel and Bartholomew were in the same garrison and fought together. Bartholomew was in awe of Castiel and his abilities, but after the fall of the angels, sent other angels and rogue Reapers to hunt Castiel down. With the help of a warding tattoo and Sam and Dean, Castiel managed to avoid Bartholomew's attacks, but was later captured by his followers. To Castiel's surprise, Bartholomew greeted him warmly, even hugging him, having apparently put aside his former anger at Castiel. Bartholomew offers Castiel the chance to help organize the angels under his rule and retake Heaven, believing that together they can do it. Bartholomew also offers Castiel the resources to track down Metatron. However, when Bartholomew tortures an angel and refuses to stop killing even innocent peaceful angels, Castiel refuses to help him, declaring that he wants no more part of slaughtering angels. When Bartholomew attacks him, Castiel is able to overpower his former friend but refuses to kill him. However, when Bartholomew attacks him while his back is turned, Castiel is forced to kill him in self-defense. In the aftermath, Castiel's unwillingness to kill and wanting to do things a different way causes some of Bartholomew's followers to see that there is a different way and decide to follow Castiel instead.
- Castiel and Bobby- Castiel and Bobby's Relationship over the years.
- Meg and Castiel - Castiel and Meg's Relationship over the years.
- Castiel and Sam - Castiel and Sam's Relationship over the years.
- Dean and Castiel - Castiel and Dean's Relationship over the years.