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.
The book can still be found in the original Bell hardback edition from 1951 and later Dover reprints. It is in descriptive notation and is sparing with its diagrams, so for my own convenience I put together a collection of the 100 games. I fear they won't mean a lot without Konig's notes, but if you have the book, here they are.
P.S. My interest in this book was rekindled by watching a lecture by Sokolov on the Lopez, where he went back to some games chosen by Konig to explain the state of theory.