Named after Warren Rue - British astronomer (1815-1889).
De La Rue is the remnant of a lunar crater, or possibly several merged craters, creating a formation sometimes called a walled plain. This formation lies to the north-northwest of the prominent crater Endymion, just beyond the eastern extreme of Mare Frigoris. The crater Strabo intrudes into the northern part 's northern rim, and the smaller Thales is attached to the northwestern part of the wall. (wikipedia entry)
A crater is a circular depression likely created by an impact event. On the Moon they are named after deceased scientists, polar explorers, astronauts or cosmonauts.