Several mustelids, including the mink, the sable (a type of marten), and the stoat (ermine), boast exquisite and valuable furs, and have been accordingly hunted since prehistoric times. From the early Middle Ages, the trade in furs was of great economic importance for northern and eastern European nations with large native populations of fur-bearing mustelids, and was a major economic impetus behind Russian expansion into Siberia and French and English expansion in North America. In recent centuries, fur farming, notably of mink, has also become widespread and provides the majority of the fur brought to market.