Just as there is a typical human life cycle that lasts about 80 years and no two are exactly the same, there is a typical empire life cycle that typically lasts about 100 years. The major phases are shown in this chart.
Once upon a time, there was a spectacular trader, who predicted the exact time and price in the market, wrote a book, and left a message. "the valuable secret, too valuable to spread broadcast, clothed in veiled language". You shall seek the secrets. It is in this library.