Messiah is simply a term that means "Anointed One" in Hebrew. There have been many people named Messiah through out Jewish history, a famous example is Cyrus the Great. But there are several examples of others like Jesus who claimed his status as the Messiah and attempted to brand the term as something like the equivalent as a Savior. In fact, just a couple decades or so after the Jesus of the Bible was killed another Jesus with a similar story led a revolt and was killed as well. Many rabbis or teachers gathered followers and preached against their oppressors and in many cases they were deemed the Messiah. So in a way yes it is more common than we sometimes think. It is less common I believe that the term is connected to a figure of salvation since it does not carry that idea historically.

Edit: Other Christ-like figures you guys might want to read about.

1. The Egyptian
2. Theudas
3. Jesus the Son of Ananias 4.Apollonius
4. Hanina ben Dosa
5. Even the Roman emperors have fun miracle stories

• I think it is important to remember that in ancient times men like this were common. Why not believe in son's of gods, miracles, etc.

When? Where?

In the eastern Roman Empire during the 1st century CE? Or in some other specific time period? Or across the past twenty centuries?

The answer is different depending on the when and the where.