Hinterland

Hinterland is a German word meaning "the land behind" (a city, a port, or similar). The term's use in English was first documented by geographer George Chisholm in his "Handbook of Commercial Geography" (1888). Originally the term was associated with the area of a port where materials for export and import are stored and shipped. Subsequently, the use of the word expanded to include any area under the influence of a particular human settlement.
Breadth of knowledge.
A further sense in which the term is commonly applied, especially by British politicians, is in talking about an individual's depth and breadth of knowledge of other matters (or lack thereof), specifically of academic, artistic, cultural, literary and scientific pursuits. For instance, one could say, "X has a vast hinterland", or "Y has no hinterland". The spread of this usage is usually credited to Denis Healey (British Defence Secretary 1964–1970, Chancellor of the Exchequer 1974–1979) and his wife Edna Healey, initially in the context of the supposed lack of hinterland of former Prime Minister Margaret Thatcher.