The 8th century BC started the first day of 800 BC and ended the last day of 701 BC.The 8th century BC was a period of great changes in civilizations. In Egypt, the 23rd and 24th dynasties led to rule from Nubia in the 25th Dynasty.The Neo-Assyrian Empire reaches the peak of its power, conquering the Kingdom of Israel as well as nearby countries.he 8th century BC started the first day of 800 BC and ended the last day of 701 BC.