Sauron reawakens in Middle-earth
Event Type: Political
Age: 2nd Age - Pre-Rings
"in Middle-earth there was peace for many years; yet the lands were for the most part savage and desolate, save only where the people of Beleriand came... And in the south and in the further east Men multiplied; and most of them turned to evil, for Sauron was at work.
Seeing the desolation of the world, Sauron said in his heart that the Valar, having overthrown Morgoth, had again forgotten Middle-earth; and his pride grew apace."
The Silmarillion, Of the Rings of Power and the Third Age
"But eventually Galadriel became aware that Sauron again, as in the ancient days of the captivity of Melkor, had been left behind. Or rather, since Sauron had as yet no single name, and his operations had not been perceived to proceed from a single evil spirit, prime servant of Melkor, she perceived that there was an evil controlling purpose abroad in the world, and that it seemed to proceed from a source further to the East, beyond Eriador and the Misty Mountains."
Unfinished Tales, Part 2, Ch IV, The History of Galadriel and Celeborn