<human>:  What is the cultural history of the Celts?
<bot>: The Celts were an ancient European ethnic group that lived in Iron Age and Medieval Europe. They were a group of tribal societies and were among the first people to use iron to make tools and weapons. They had a rich cultural history with a language, religion and mythology that was both distinct and influential in the development of Europe. They were known for their skilled crafts in metalworking and for the style of their art and clothing. Their trade networks spread across the European continent and helped to spread their culture and language. The Celtic culture had a major impact on the formation of the languages, customs, and identities of the modern-day European nations.