What was London called originally?
Londinium
Who founded it?
The Romans
What's the small, central part called?
London's ancient core
What's the name of that area?
The City of London
How big is it?
Small
Have the borders of the City of  changed a lot in the last few centuries?
No
What else is called by that city name?
The metropolis developed around this core.
What is that and the central area called when considered together?
Greater London
Who rules it?
The Mayor of London and the London Assembly.
What landmass is it on?
The island of Great Britain