Board Thread:Suggestions forum/@comment-27200931-20170510192310/@comment-27200931-20170513151141

"'Authority is not given to you, Steward of Gondor, to order the hour of your death,' answered Gandalf. 'And only the heathen kings, under the domination of the Dark Power, did thus, slaying themselves in pride and despair, murdering their kin to ease their own death.'"

The meaning of heathen (http://www.dictionary.com/browse/heathen):


 * 1 - (in historical contexts) an individual of a people that do not acknowledge the God of the Bible; a person who is neither a Jew, Christian, nor Muslim; a pagan.
 * 2 - Informal. an irreligious, uncultured, or uncivilized person.
 * 3 - of or relating to heathens; pagan.
 * 4 - Informal. irreligious, uncultured, or uncivilized.

It's clear that Tolkien meant that the kings, those who serve Sauron, are barbaric.