Heren Istarion

Heren Istarion was the title assigned to the Istari of the Third Age. None except Elrond, Círdan, and Galadriel knew of what kind and from where they came. Among Men it was initially assumed that the wizards were also men who by long and secret study had acquired great knowledge of lore and arts. However, as the Third Age passed it was marked that the wizards did not die and so Men began to believe that they were of Elven-kind.
In truth the Heren Istarion had been created in Valinor. A council of the Valar was called by Manwë which resolved to send three emissaries. Initially only Curumo (Saruman), chosen by Aulë, and Alatar, chosen by Oromë, stepped forward. Manwë then asked for Olórin (Gandalf) and commanded him to go. Curumo took Aiwendil (Radagast) with him because Yavanna begged him to do so and Alatar took along his friend Pallando.
Círdan witnessed the landing of the Order c. T.A. 1000. Their "mission" was to advise and persuade Men and Elves to resist Sauron. The number of members of the Heren Istarion was unknown but to the North of Middle-earth came five. One was clad in white, two in sea-blue, one in earthen brown, and one in grey.
The wizard in white was Saruman, regarded by all as leader of the order. The two in blue were Alatar and Pallando, who journeyed far into the East and South. The one in brown was Radagast and the one in grey was Gandalf, seemingly the oldest and the least of the Order.
The Heren Istarion came to an end with the passing of Sauron. Saruman died in Middle-earth and was not allowed to return to the West. Gandalf, who remained true to the mission of the Order, departed from Middle-earth in 3021. The fate of the other three wizards who landed in the North is unknown.