Complex sentence: It was used in medieval times, when it can be seen as roughly corresponding to an English shire, and was revived as an administrative subdivision during the period of Nazi Germany in 1938--1945.
Split into simpler sentences: It was used in medieval times, when it can be seen as roughly corresponding to an English shire. The administrative use of the term was revived as a subdivision during the period of Nazi Germany in 1938--1945.