'Istari' translates to mean: 'Wise Ones'. ('Istari' is plural, the singular is 'Istar').

An order of Wizards that first appeared in Middle-earth around 1000 of the Third Age. Their names in Valinor were Curumo, Olórin, Aiwendil, Alatar and Pallando. The first three had many names, and are also known as Saruman, Gandalf and Radagast.

They were sent by the Valar to oppose Sauron. They were not allowed to do this by holding great power over Elves and Men, they were supposed to unite them by advising and guiding. The chief of the order was Curumo, who entered Middle-earth first.

They took mortal bodies, and were not allowed to show themselves as Maiar. They came looking like old men but were still hale. They did not change or age with the years, and were always gathering wisdom. Their bodies were subject to mortal things such as hunger, tiredness and death, but their spirits were not.

In the end, only one is said to have been faithful to their orders: Gandalf. Saruman was corrupted by evil, and Radagast gave up the mission for his love for birds and beasts. The two Blue Wizards passed into the East, and were never seen again.
Encyclopedia entry originally written by Hathaldir