Comments:

First published in two parts in Galaxy, December 1963 and February 1964.

From Wikipedia:

Star King (also published as The Star King) is a science fiction novel by American writer Jack Vance, the first in his Demon Princes series. It tells the story of a young man, Kirth Gersen, who sets out to track down and revenge himself upon the first of the Demon Princes, the five arch-criminals who massacred or enslaved nearly all the inhabitants of his colony world when he was a child.

The antagonist of the book was originally known as Grendel the Monster, and was subsequently renamed Attel Malagate for the novel version. (Accessed 12 March 2019)

Quotes:

   “Will you stay awhile, Mr. Gersen?”
   “Two or three days, perhaps. I have things to think over.”
   Smade nodded in profound understanding. “We’re slack just now; just you and the Star King. You’ll find all the quiet you need.”
   “I’ll be pleased for that,” said Gersen, which was quite true; his just-completed affairs had left him with a set of unresolved qualms. He turned away, then halted and looked back as Smade’s words penetrated his consciousness. “There’s a Star King here at the tavern?”
   “He has presented himself so.”
   “I’ve never seen a Star King. Not that I know of.”
   Smade nodded politely to indicate that the gossip had reached to the allowable limits of particularity. He indicated the tavern clock: “Our local time; better set your watch. Supper at seven o’clock: just half an hour.”

   Tristano fell back, now startled. For an instant he sat laxly asprawl. Gersen caught Tristano’s leg and ankle in a lock, threw over his weight, and felt the bone snap. Tristano sucked in his breath. Snatching for his knife, he left his throat exposed; Gersen hacked backhand at the larynx. Tristano’s throat was well-muscled, and he retained consciousness, to fall back, feebly waving his knife. Gersen kicked it away, edged forward carefully, for Tristano might be equipped with one or a dozen secret built-in weapons.
   Leave me be,” croaked Tristano. “Leave me be, go your way.” He dragged himself to the wall. (more)

Republished as The Star King and in the collection Demon Princes, both Spatterlight, 2012.