Rowan was a powerful Vampire, who served as a top messenger and minion to his Queen. In that capacity, he came to the apartment of Cole Turner, the new host to the Source of All Evil, and proposed lifting the vampires' exile in exchange for his clan and queen's loyalty. He met Paige Matthews when she came to the apartment to talk to Cole about Phoebe Halliwell. Talking in the elevator with Paige, the two expressed a common dislike and mistrust for Cole - common, that is, despite their opposing bents and reasons for it.
From there, Rowan would be employed by his queen to hunt Paige and turn her into a vampire. He led a flock of vampires in bat form in attacking Paige and turning her into a vampire. He and his Queen suggested that for her first meal, she feed on her sisters in hopes of turning all of the Charmed Ones into vampires. They thought that if they could get all three Charmed Ones on their side, they'd be able to take control of the underworld before Source Cole was able to consolidate his power.
While trying to help Paige complete her conversion by sucking her sisters' blood, Rowan was vanquished when Phoebe impaled him with a stake.