Global history map

You've probably seen maps of certain regions of the world that show the changes of the balance of power, as one Kingdom comes to ascendancy and then falls, or languages change over time, or different cultures inhabit different areas.

It would be cool to have a website with one map of the world that shows such events. You would have a slider to go forward and backward in time. You could turn off and on certain features, like city locations, languages, spread of inventions, domesticated animals, the publishing of certain books, religions,etc.

So there would be basically two things: 1. Area maps that show the spread of cultures, languages, political factions, technologies such as certain stone tools or building types, etc. 2. Point events, showing things like influential people, cities, events like battles or revolutions, publication of books, etc.

The inputting of data could be crowdsourced. For events that scholars disagree about, you could have options to show alternative theories.

If you wanted to show something like the rise and all of the Roman Empire, you have set animations, where the mediterranean was focused on in the map, and you watch the growing political influence of Rome, see various point events pop up, such as battles, influential people, conquered cities, the creation of cultural works, etc.