This is the 7528th most frequent Polish word.
krzyżakach
"Krzyżakach" is the locative plural form of "Krzyżak," meaning "Teutonic Knights."
In this context, 'krzyżakach' refers to the historical Teutonic Knights, used as a noun in locative case.
Brat opowiadał o krzyżakach, którzy walczyli z Polakami.
My brother talked about the Teutonic Knights who fought against the Poles.
Here, 'krzyżakach' again refers to the Teutonic Knights, in the locative case, showing historical inhabitants of castles.
W książce znajdziesz informacje o krzyżakach zamieszkujących średniowieczne zamki.
In the book, you will find information about the Teutonic Knights inhabiting medieval castles.
In this use, 'krzyżakach' is the noun in locative case, referring to the topic of Teutonic Knights discussed in an essay.