The increasing power of the Númenóreans had a dark side; the exploitation of Middle-earth's forests had devastated large regions of Eriador. The Númenóreans established further settlements in Middle-earth, coming to rule a coastal empire with no rival. At first they had engaged with the Men of Middle-earth in a friendly manner, but Minastir's successors, Tar-Ciryatan and Tar-Atanamir 'the Great', became increasingly tyrannical, oppressing the Men of Middle-earth and exacting heavy tribute.