One of my favorite English-language sources for 17th century Poland: the Diary of Patrick Gordon of Auchleuchries

[u/chevalier100]

Patrick Gordon was a Catholic Scotsman who attended a Jesuit college in Poland for a few years before dropping out and joining the Swedish army. He fought in the Second Northern War (“the Deluge”), switching sides between Sweden and Poland-Lithuania a few times. When the war was over, the only employment he could find was with Muscovy, where he stayed for the rest of his life, ultimately rising to the rank of general.

His Diary is one of the best English-language primary sources for 17th century Poland. He describes battles, but also his encounters with many civilians. Volume 2 of his diary even has a passage where he reflects on how much better the PLC is to Muscovy.

While the diary is widely available online, most editions are incomplete backtranslations from a 19th century German translation. That’s why I was so happy to recently discover that the University of Aberdeen put their edition of the original diary online for free: https://www.fulcrum.org/concern/monographs/h702q925m