None of the specifics of this collection (prose, illustration, plots) really wowed me, but I was pleased overall with getting an assortment of varied and less familiar stories.
A few felt like they were edited down from longer versions, which might have made more sense, but I don't know for sure. There are end notes, but they are very brief. Still, better than no notes!
Eg, note for the title story: this story preserves the age-old rivalry between the fairy people, who inherit their magic, and the wizards, who learn theirs as apprentices. I first read it in one of the great collections of fairy tales compiled by Andrew Lang in the nineteenth century. Lang gives his source as the Cabinet de Fees.
Stories in this volume:
The Wizard King
The Partridge Spirit (collected by Charles Leland)
The Magician's Horse (modern Greece)
Witch of Rollright (about the Rollright Stones)
Ivan and the Wizard (Russian)
The Boy Magician (Hopi)
The Wizard Who Got Sick (Armenia--this wizard does good deeds)
Pome and Peel (Umbria)
The story of Merlin from Geoffrey of Monmouth