Fate of empires

1
http://people.uncw.edu/kozloffm/glubb.pdf

I found this little book,which was referred to in the documentary Four horsemen by Ross Ashcroft.
It is amazing and answers many doubts about the direction of our world,even the source of many of our personal problems.
To avoid being off topic,Id like to ask if anyone has ever devised a way to chart the start and end of an empire. A few are mentioned in the book, but I dont know which date should be used for each, and I certainly dont know what chart I should use for a future Chinese empire. The revolution chart? Or was there a date the Chinese government decided to change its policy regarding their attitude to the world?