This is one of my favourite books and though rather dated (the last game cited is from 1948) it's also extremely instructive.
In 100 annotated games, Konig discusses the opening theory of four openings: the Ruy Lopez, Queen's Gambit, English Opening and King's Gambit.
It takes an evolutionary approach to chess theory, and instead of jumping in to contemporary theory, tells the story of how that theory came about. So we trace the English Opening from Staunton's new(!) approach in 1843 to Golombek's ideas in 1939.
Lockdown and subsequent restrictions have given me time to browse
the dustier reaches of my chess library, including Napier's Paul
Morphy and the Golden Age of Chess, a compilation of his
three booklets Amenities and Background of Chess, each a
selection of 100 lightly annotated games to amuse and provide an
educative ABC. Horowitz edited this combined work and commented:
I started coaching adults at the Exeter club in 1993, about the same time as Alan Maynard started up the current incarnation of Exeter Junior Chess Club. I went looking for some useful resources for teaching, and there were some, but mostly I became a magpie, picking shiny bits out of various good books. I did find it irksome that so many books repeated familiar examples, and I thought I could at least pull those out for my colleagues, and that became the core of the Canon. I found particularly useful:
* Tony Gillam - Simple Chess Tactics and Simple Checkmates