Simplify the following text for a Grade 16 native English-speaking person.
Original: For the encyclopedia 's purposes , Bangladesh is defined as the territory comprising ancient Eastern India , Suba Bangla , Shahi Bangalah , Mughal Suba Bangla , Bengal Presidency , Bengal Province , East Bengal , East Pakistan , and the independent Bangladesh , in historical succession .
Simplified: Although Bangladesh is a new country , there is a lot of history going back many , Banglapedia uses the word Bangladesh to include the territory of ancient Eastern India , Suba Bangla , Shahi Bangalah , Mughal Suba Bangla , Bengal Presidency , Bengal Province , East Bengal , East Pakistan , and the independent Bangladesh .