The Istari

[Legolas]

Here it is, Manwe. Found in footnote 3 for the Istari chapter of Unfinished Tales.

I think they went as emissaries to distant regions, East and South, far out of Numenorean range: missionaries to enemy-occupied lands, as it were. What success they had I do not know; but I fear that they failed, as Saruman did, though doubtless in different ways; and I suspect they were founders or beginners of secret cults and 'magic' traditions that outlasted the fall of Sauron.