Province or Voivodeship Both words are used in English just as canton and department are, they don’t require "specialised knowledge" just a bit of general knowledge about the world.
It would not be unusual to use these in Englandshire.
The most important mistake make by UE (and other) translators is the confusion the old historical term with contemporary symbolic one. Wojewoda and wojewodztwo are historical title and historical type of local authorities organization specific only for Slavic nations. There are no any English translation for them, just equivalents. May be during historical discussions between professionals they use phrases: "voivod hanged this or that man" or "conquerred sth." or even "lost his voivodship" but this is rather a facilitation for stiff English tongues, not a translation.
It is essential to understand that a contemporary Polish wojewodztwo/province have nothing to do with a historical wojewodztwo leaded by historical wojewoda. There are just a traditional names used in Polish language. What more, good translation means matching "our" term to closest term "they" use in real life, not a theoretical one. Term "province" fulfilles this condition in the best way.
What I wrote above explains also why sometimes we can (and sometimes can not) find translation "voivodship" in dictionaries.