I had an excellent person to leave as regent while I’m away
(This was not the great magic horn of Narnia, Queen Susan’s Horn: he had left that at home for his regent Trumpkin to use if any great need fell upon the land in the King’s absence.) Drinian, who was on the look-out for a signal, recognized the royal horn at once and the Dawn Treader began standing in to shore.
And instruct my regent, the Dwarf Trumpkin, to give to all these, my shipmates, the rewards I promised them.
And if I come not again it is my will that the Regent, and Master Cornelius, and Trufflehunter the Badger, and the Lord Drinian choose a King of Narnia with the consent-
There are no more uses of "regent" in the book.
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The California Board of Regents voted to increase student fees 32% at all University of California schools.
The King was captured, so his son served as Regent in his absence.