Istari

The Istari were five Maiar spirits who took forms of humans against Sauron, who was rising in power.

They were called Wizards in Middle-earth.

History
In the end of the Third Age, the Wizards passed from sight; since, with the fall of Sauron, their work was done. Gandalf passed over the Sea with the Last Riding of the Keepers of the Rings. Saruman became a naked spirit and wandered Middle-earth forever, due to his banishment from Valinor. Radagast remained in Middle-earth, tending to the wilderness. The fate of the Blue Wizards is unknown.