The Path of the King is a 1921 novel by the Scottish author John Buchan, presented as a loosely-coupled series of short stories.
In a prologue to the novel, three men discuss around a campfire the notion that the 'spark' of masterful men may be transmitted down from generation to generation, and even though it may smoulder for generations and may seem lost, will reappear and flare up when the time is right.
Less"I saw the younger sons carry the royal blood far down among the people, down even into the kennels of the outcast. Generations follow, oblivious of the high beginnings, but there is that in the stock which is fated to endure. The sons and daughters blunder and sin and perish, but the race goes on, for there is a fierce stuff of life in it. ... Some rags of greatness always cling to it, the dumb faith that sometime and somehow that blood drawn from kings it never knew will be royal again. Though nature is wasteful of material things, there is no waste of spirit. And then after long years there comes, unheralded and unlooked for, the day of the Appointed Time".