Knight on Horseback

From Author Wars - https://authorwars.com/publications/knight-on-horseback-19656.html

Overview:

Title: Knight on Horseback
Author: Ann Rabinowitz
Year: 1987
ISBN-10: 0027756602
Publisher: Macmillan
Price: $13.95
Pages: 197
Binding: Hardcover
Type: Novel
Title Reference: Knight on Horseback
Notes: Cover artist on front flap of Archive.org copy; spelled Valkenburgh on p. 18 here, http://www.r3.org/wp-content/uploads/2018/06/winter-1994-06-12-2018_15-28-50-159.pdf, and Valkenburgh did covers for other Macmillan books, so almost certainly the same artist. Stated first edition, first printing with full number line.