Who conquered Celtic tribes?

The Celtic tribes were primarily conquered by the Roman Empire during the period of Roman expansion in the 1st century BCE. Julius Caesar led military campaigns in Gaul (modern-day France) from 58 to 50 BCE, effectively subjugating various Celtic tribes. Additionally, the Romans continued to assert control over Celtic regions in Britain and other parts of Europe throughout the subsequent centuries. The conquest led to significant cultural and political changes in these areas.