The first settlements in the area date back to prehistory. Later on, Celts, German tribes resides in the valleys until they left in 5th century. Later came Lusatian Sorbs. In the 14th century, German-speaking colonists came and started clearing of the dense primeval forests. Permanent settlements were established. In the 16th century, several glass works were founded. Glassmaking had a profound effect on the ecosystem. The primeval forest was gradually replaced by fast-growing spruce monoculture. Other important industries included tin-mining, metallurgy and textile.