Things of Middle-earth
Banner of Sauron, The
Other Names: The Red Eye
Description:Sauron turned north and made at once for Eregion. ... At last the attackers ... captured the chief object of Sauron's assault, the House of the Mírdain, where were their smithies and their treasures. Celebrimbor, desperate, himself withstood Sauron on the steps of the great door of the Mírdain; but he was grappled and taken captive ... Concerning the Three Rings Sauron could learn nothing from Celebrimbor ...
In black anger he turned back to battle; and bearing as a banner Celebrimbor's body hung upon a pole, shot through with Orc-arrows, he turned upon the forces of Elrond.
Unfinished Tales, Part 2, Ch 4, The History of Galadriel and Celeborn: Concerning Galadriel and Celeborn
There can be no doubt that Sauron, well-informed of the [Last] Alliance, had sent out such Orc-troops of the Red Eye as he could spare, to do what they could to harry any forces that attempted to shorten their road by crossing the Mountains. ... [Author's note.
Unfinished Tales, Part 3, Ch 1, The Disaster of the Gladden Fields: Notes, Note 20
He [Mouth of Sauron] it was that now rode out, and with him came only a small company of black-harnessed soldiery, and a single banner, black but bearing on it in red the Evil Eye.
The Return of the King, LoTR Book 5, Ch 10, The Black Gate Opens
Contributors: Elena Tiriel 6.24.04; added Name & quote: ET 7.15.04