Why are French, Italian, Portuguese, Spanish and Romanian sometimes refer to as romance languages?

These languages are referred to as Romance languages because they all evolved from Latin, which was spoken by the Romans. Latin was the dominant language of the Roman Empire, and as the empire collapsed, Latin evolved and eventually split into different regional dialects that became the basis for these modern languages. The term "Romance" comes from the Latin word "romanice" which means "in the Roman way" or "in the Roman language".