I am a big fan of Glen Cook's literature, granted my first exposure to it was with Tyranny of the Night. I soon began going through the Black Company wanting the same fix of dark fantasy.
While reading one of the Black Company books (unsure of which) I see a familiar quote and it began stirring up more questions when it came to the world that it all took place in. Note that I am paraphrasing the following. "Fear the Tyranny of the Night." Which is a mantra repeated in the Instrumentalities series.
I've looked and looked for a world map of Instrumentalities with no luck, but am I the only one who believes that The Black Company series takes place before the Instrumentalities?