What contributed to changing periods in history?

In general, there are five periods in the historical process. Their scope is not precisely defined, but they can be delineated by particularly important events. For example, the replacement of Primitive society by the most ancient stage occurred due to the development of property relations. People were divided into haves and have-nots. Often the change of periods was prompted by a particularly striking event, for example, the collapse of the Roman Empire. The transition to modern times is characterized by the emergence of capitalist relations. That is, before each stage, something unconventionally new happens, atypical for the past period.