Definition of "kinglet"

Cæsar termeth all the Lords, which in his time had justice in France, to be Kinglets [tr. reguli], or pettie Kings.

1603, Michel de Montaigne, chapter 42, in John Florio, transl., The Essayes […], book I, London: […] Val[entine] Simmes for Edward Blount […]

“My son hears tales. In the viceroy’s personal entourage, one could scarcely help it. And he tells me of them. Our new viceroy would not refuse the Crown if offered, but he guards his line of retreat. There are stories that, failing Imperial heights, he plans to carve out a new Empire in the Barbarian hinterland. It is said, but I don’t vouch for this, that he has already given one of his daughters as wife to a Kinglet somewhere in the uncharted Periphery.”

1951, Isaac Asimov, Foundation (1974 Panther Books Ltd publication), part V, chapter 10, pages 160–161