* Historically: In many pre-industrial societies, formal schooling wasn't common for most children. Education, if any, happened informally within the family or community, focusing on practical skills. When formal schooling did exist, it often began later, perhaps in the pre-teen or teenage years, and was mostly for the elite.
* 19th and early 20th centuries: The age of compulsory schooling gradually decreased. In many Western countries, it started around age 6 or 7, but many children, particularly those from poorer families, didn't attend regularly or for very long.
* Mid-20th century to present: In many developed nations, compulsory education begins around age 5 or 6 and continues to at least age 16. However, preschool programs are increasingly common for younger children.
To get a more precise answer, you need to specify:
* The country or region: Schooling ages differ significantly between countries.
* The time period: School attendance ages have changed dramatically over time.
* The social class: Access to education has historically been linked to social class.
For example, if you're interested in the age children attended school in England in 1850, that's a very different question than asking about the age in the United States in 2023.