From the Return of the King, by J.R.R. Tolkien-

Gandalf speaking to Lord Denethor, the steward of Gondor:

But I will say this: the rule of no realm is mine, neither of Gondor nor any other, great or small. But all worthy things that are in peril as the world now stands, those are my care. And for my part, I shall not wholly fail of my task, though Gondor should perish, if anything passes through this night that can still grow fair or bear fruit and flower again in days to come. For I also am a steward. Did you not know?