The Sanguine Rose (sometimes called Sanguine's Rose) is a Daedric artifact created by the Daedric Prince Sanguine. It can take on many forms, including that of an actual rose, a wooden stave carved like a rose or a staff-sized rose. Although powerful, the Rose is not an artifact most would care to possess. It can be used to summon a lesser Daedra, who will attack all except the holder. The Daedra is uncontrollable, unlike those summoned by Conjuration, but as with conjured creatures it is only bound to the mortal plane temporarily. Each time the Rose is used it wilts a little, and when all the petals fall off, it loses its power. When this happens, a new rose blooms somewhere in Oblivion and is plucked by Sanguine to be given to another champion.
Just before the events of the Warp in the West, an unknown agent of the Blades was sent by Sanguine to kill a monk who had slain his worshippers. Sanguine promised the Rose as a reward, despite the fact that it had been set aside for his favored disciples. The agent accomplished the task, and was given the Rose by a worshipper of the Prince.
Sometime after these events, a group of apprentices from the Mages Guild who had turned to Daedric magic came into the possession of the Rose. The young Martin Septim was a part of this group and possessed the Rose for a time. The group's dabblings in Daedric magic soon turned dangerous, and many of them died, although the circumstances are not understood. This caused Martin to turn away from Sanguine and become a priest, losing the Rose in the process.
In 3E 433, Sanguine offered the Rose to the Champion of Cyrodiil in return for disrupting a formal dinner hosted by Countess Alessia Caro of Leyawiin. The Champion infiltrated the party and cast a spell supplied by the Prince, which stripped all attending of their clothing, including the Champion. Sanguine was pleased and rewarded the Champion with the Rose. An article on the prank was published by the Black Horse Courier in a special edition paper titled Pranks Spoils Society Gathering!.
In 4E 201, Sanguine manifested himself as a Breton man named Sam Guevenne. For his own amusement, he challenged the Last Dragonborn to a drinking competition in a tavern in Skyrim, after which the two drunkenly explored the province on a quest to repair the Rose. The Dragonborn couldn't remember the events the next day, and traced their steps across Skyrim, collecting the items necessary to repair this promised staff. The Dragonborn eventually caught up with Sam, who revealed his true identity and told the Dragonborn that the items weren't needed and it was more for Sanguine's fun than anything else. The Prince then gave the Dragonborn his Rose as a prize for amusing him.