period · phase

The space race was an exciting time in history.

He amassed a fortune in stock trading during the last boom.

For a long time, society was strongly hierarchical and unequal, primarily composed of peasants. The most backward, impoverished segment of the population, they were crushed by the weight of taxes, wars, and famines.

The first lute was invented during the Qin dynasty.

The religion was in its glory in those days.