How did the popularities of Roman given names evolve over time?

1. Why did Romans change their names?
2. How did the Roman naming system work?
3. When did Roman names stop being used?

Why did Romans change their names?

Originally Roman women shared the binomial nomenclature of men; but over time the praenomen became less useful as a distinguishing element, and women's praenomina were gradually discarded, or replaced by informal names.

How did the Roman naming system work?

At least two names were necessary for Roman men, the praenomen (first name, given name) and nomen (principal name, gens name). The nomen usually ended in -ius. Many had a third name, the cognomen (additional name, nickname; often denoted a branch of a family).

When did Roman names stop being used?

People in the Roman world discontinued using complete Roman names over a period of centuries in late antiquity and the early middle ages. By about 500 or 600 almost everyone would have just used their personal name, without any clan or family name.