I find this author quite readable (
here, and
here). Motive for reading this book - I know so little about Poland, yet it appears my wife has about 3/4 of her heritage there (meaning 3/8 for our kids) - that's a lot.

Zamoyski comes from a family with a long history in Polish nobility.
So what did I learn? Way too much to keep straight, but some useful strands:
1. Poland had very large land territories at various stages in what I'll call early-modern times. Arrangements with Lithuania, Ruthenia (Ukraine), etc. Often lightly populated and loosely controlled - but a large power player.
2. Russia got stronger. German states got stronger, culminating in 19th century unification. But even somewhat before that - an essential issue for Poland is its unfortunate position between Russia and Germany. A huge effect on its history especially in early 18th century and after.
3. Hard to believe that Poland was simply partitioned off the map following a sequence of moves primarily involving Germany, Austria, Russia. Polish politics wrapped up in regaining the homeland; less experience addressing practical governance.
4. And of course there was the Soviet era.
5. Farther back - a governing method that involved an elective king and required lots of consensus - in some ways probably quite modern - but in the end this paralyzed the state.
6. As I've gotten to understand better - in part because of the Zamoyski books linked above - the concept of the "nation" and "patriotism" are incredibly slippery, and dangerous. So much is invented after the fact for reasons of state. There does seem to be a core . . . but on the margins, what really is "Poland" and "Polish?" Borders and peoples have moved around for as far back as our knowledge extends.
7. A consequence of being positioned so far east - Cossacks, Tatars, Turks. Important roles in fighting the Ottomans.
8. And the incredibly large Jewish population - at least compared to other European countries - lightly-populated areas welcomed Jews getting kicked out of western European countries. Though once in place - often mistreated.
9. Roman Catholicism certainly not a sure thing! Look at the geography.
10. Lots of diplomatic noise in 19th and 20th century about re-forming a nation of Poland - but mostly talk, as the balance of power seemed to work - and radical change like this could upset things. Short-lived state post WWI.