Over 14 seasons, Supernatural's Sam and Dean Winchester have established a chosen family of their own. That ragtag group includes Bobby, the boys' surrogate father and fellow monster hunter, Castiel, a brother in arms who also happens to be angel, and Jack, an adoptive son and Nephilim. However, the Winchester brothers boast quite a monster-hunting legacy through their blood relatives. Despite the limited presence of other family members in their lives, throughout the show, we've learned more and more about their parents, grandparents, and even their half-brother, Adam.
Let's take a deep dive into all things Winchester -- and Campbell -- and see just how the boys' family tree set them up to be the master supernatural fighters they are.
THE PARENTS: JOHN AND MARY WINCHESTER
In the beginning of the show, Sam and Dean's monster-hunting fate seemed to be the result of their mother's and father's choices. The Winchesters -- father John, mother Mary (née Campbell), older brother Dean, and younger brother Sam -- lived a normal suburban life in Lawrence, Kansas. Then one night when Sam was just six-months old, a yellow-eyed demon came into his room. Mary caught him in the act of feeding blood to her baby. So, the demon killed Mary and burned the house down.
After that night, John became obsessed with finding the demon, Azazel, who murdered his wife. In the process, he learned all he could about the supernatural. He became a hunter and began a nomadic existence with his young sons. They moved from town to town as John looked for monsters to hunt and searched for Azazel. Sam and Dean were often left on their own. However, John also trained them to hunt and taught them supernatural lore.
For a long time, the boys believed their father was the sole reason they became hunters. After he made a deal with Azazel in which he traded his life for an ailing Dean's, as far as they knew, they had no more family ties to hunting. However, in the Season 4 episode, "In the Beginning," Dean travels back in time to 1973 and learns the truth: his mother comes from a long line of hunters and was raised in the life just like Sam and Dean were.
When she was young, Mary was determined to have a family and live a safe, normal life. That was one of the reasons she chose to marry John who knew nothing about the supernatural. Unfortunately, before she and John were married, Mary drew the attention of Azazel. Azazel killed Mary's parents and John, but offered to bring John back if Mary agreed to let Azazel come into her house in 10 years time. Heartbroken at her losses, Mary agreed, sealing both her and her sons' fates.
Decades later, at the end of season 11, Mary was brought back to life by the Darkness as a reward for Dean reuniting her with her brother, God. Mary resumes life as a hunter like her now-adult sons and her talent for it is on full display in seasons 12 through 14. Sadly, Mary meets her fate once more when a soulless Jack accidentally kills her in a fit of rage.
THE MATERNAL GRANDPARENTS: THE CAMPBELLS
Mary was the only child of Samuel and Deanna Campbell, who Sam and Dean are named after. The Campbells had been fighting the supernatural for generations and expected Mary to continue that legacy. Despite the family's long association with hunting, when Dean first met Samuel in 1973, he made it clear that he didn't trust other hunters and preferred to work alone or with his family.
After dying at Azazel's hand in 1973, Samuel was later resurrected by Crowley, the new king of Hell. In Supernatural's sixth season, it was revealed that both he and a resurrected Sam had been hunting together, along with some other Campbell relatives, for a year while Dean attempted to live a normal life with girlfriend Lisa and her son Ben. Samuel was a master hunter with a thorough knowledge of the supernatural and Sam and Dean learned a lot from him, including things like a cure for vampirism. Yet, Samuel was secretly working for Crowley in exchange for the resurrection of his daughter Mary. Eventually Sam took Samuel out.
THE PATERNAL GRANDFATHER: HENRY WINCHESTER
The Winchester family legacy with the supernatural deepened further when Sam and Dean met their paternal grandfather, Henry Winchester. All Sam and Dean knew about John's father was that he left one night when John was boy and never returned. Presumably John was raised by his mother, Millie, however little is known about her. In Season 8, however, the boys discovered what really happened.
Henry was a member of the Men of Letters, a secret organization whose goal Is to chronicle and observe the supernatural. Just as the Campbells had been monster hunters for generations, the Winchesters had been Men of Letters for generations. Henry dreamed that his son and his grandsons would carry on the family tradition.
On the day of Henry's final initiation, Abaddon, a Knight of Hell, infiltrated the organization and massacred its members. Henry channeled his soul to time travel to the future where he met his grandsons and worked with them to thwart Abaddon. Before he perished, Henry taught Sam and Dean tricks like how to carve devil's traps into bullets. He also gave Sam and Dean the keys to the long-abandoned Men of Letters bunker. It's been the boys' base of operations ever since and has given them access to a wealth of information about all things supernatural.
THE SURPRISE HALF-BROTHER: ADAM MILLIGAN
The family member with the least knowledge of monster hunting is Adam Milligan, John's third son. John never told his older sons about their half-brother and never told Adam about the supernatural. Dean and Sam don't learn about Adam until after he's died at the hands of ghouls in Season 4.
In Season 5, Adam is resurrected in order to serve as a vessel for the archangel Michael after Dean repeatedly refuses. Although Dean is the preferred option, Adam's ties to the Winchester make him an acceptable substitute. Sam and Dean try to save Adam but in the Season 5 finale, "Swan Song," but Michael takes over Adam's body and faces off against Lucifer, who is in Sam's body. Sam regains control just long enough to jump into Lucifer's cage in Hell. When Michael attempts to stop him, Sam drags him down too.
While Sam was resurrected soon afterward, Adam's been stuck in the cage with Michael ever since. Could Adam finally reappear in the upcoming fifteenth and final season of Supernatural? Fans everywhere have their fingers crossed.