Welsh cuisine butter was the primary cooking medium and basis for sauces. Salt was an important ingredient in Welsh butter, but also in early Welsh cheeses, which would sit in brine during the cheesemaking process. The Welsh were also early adopters of roasting cheese. An early incarnation of Welsh rarebit was being made in medieval times, and by the middle of the 15th century rarebit was considered a national dish. The acid soil of Wales meant that the milk produced by their cattle created a soft cheese, which was not as good for roasting, so Welsh people would trade for harder cheeses
History of the Welsh language speaking Cumbric, and those in the south-west, speaking what would become Cornish, and so the languages diverged. The Book of Aneirin ("Canu Aneirin", c. AD 600) and the Poetry, or Book, of Taliesin ("Canu Taliesin") belong to this era, though both also include some poems originally written in Primitive Welsh. Middle Welsh () is the label attached to the Welsh of the 12th to 14th centuries, of which much more remains than for any earlier period. This is the language of nearly all surviving early manuscripts of the "Mabinogion", although the tales themselves are certainly much older. It is also