First post ever!

I wish i knew a better way to describe this....

What do you call the type of map that shows changes to an Empire over time?... for example, with the Roman empire, the map might start with the city of Rome at a certain date, then expand to all of Italy later, then end with the furthest extent of Rome at a later year.

I feel like there has to be a name for this type of time based morphing map.

Here is an example....

http://en.wikipedia.org/wiki/Image:T...s_in_China.gif

rekaj