Rowena is an extremely powerful natural-born [[witch]], originally from Scotland in the 17th century (or possibly earlier). Before Rowena became a witch she was a peasant and the daughter of a tanner, who had an affair with a man above her social class. Once her son Fergus was born the man abandoned the two and went back to his rich wife and her grand house. Her son Fergus Roderick MacLeod, would father [[Gavin MacLeod]] and go on to become known as the demon [[Crowley]].
Rowena would flee her village and abandon Fergus after she was charged with practicing witchcraft. Rowena then studied under the great Milanese witch Leticia D’Albioni and joined the [[Grand Coven]]. The Grand Coven were critical of Rowena having a child with a "non-magic", but they were willing to overlook this because of the great talent she possessed.
Rowena was expelled from the Grand Coven because her magic was considered too extreme; one [[spell]] she created was the ''Defigere Et Depurgare'', which was used to vanquish [[demons]]. Rowena's "unpleasantness" with the Grand Coven would ultimately lead to her being hexed by the coven with a binding spell that restrained her magic, as well as being banned from performing magic, taking on students, or forming her own coven.
In 2014, 300 years later, Rowena resurfaced to reclaim her lost power base. After being captured by Crowley, she made several attempts to use him for her own ends. Crowley was aware of Rowena's manipulations, yet captured the head of the Grand Coven, [[Olivette]], for her. Under torture by Rowena, Olivette revealed the Grand Coven was much-diminished in its power because of a concerted campaign against witches by the [[Men of Letters]].
Rowena was initially antagonistic towards the Winchesters as she saw Crowley's relationship with them as diminishing his power. The Winchesters often called on her help with magic, and Rowena assisted when she saw a benefit for herself. Over time, she became an ally in their battles, albeit motivated by the benefit she saw for herself in helping them. Rowena had a particular bond with Sam -- they were both tortured by [[Lucifer]]
and saw his true face, and share the struggle of living with that experience.
In 2018, Rowena began killing people and their [[reapers]] to get [[Death]]'s attention, as she blamed herself for Crowley's death and the path that her abandonment led him down in life. During this, the reaper [[Jessica]] reveals that in the book [[Death]] keeps on her, it is written that she will die by Sam Winchester
's hand. While [[Billie]] refused to bring Crowley back, the experience ended with Rowena deciding that working for the greater good will serve as her [[redemption]] for her past actions. She subsequently aided the Winchesters in their efforts to return to [[Apocalypse World]] and on occasions when they needed her expertise on a situation or case.
In 2019, after the release of the [[Hell Ghosts]] upon the world, Rowena chose to sacrifice herself to save the world by using her own body to imprison all of the souls and demons and cast them back into Hell. At Rowena's request, and with great reluctance, Sam was indeed the one who fatally stabbed Rowena. Following Rowena's death, Sam inherited [[Rowena's Spellbooks|her magical stash]], which she intended since Sam was described by Dean as "Rowena's protégé."