Cashmere

Cashmere does not refer to a specific breed of the domestic goat but rather to the downy undercoat that all goats except the Angoras, which only have one coat, have to various degrees. The main purpose of the undercoat, as in all animals that are equipped with one, is insulation and that makes it such a great fibre for warmth in your knits. As it is so effective at keeping them warm in the extreme cold of their native lands, the goat will naturally shed this layer in the warmer months and regrow it in the cooler months. Breeders have been selecting for this trait and so there are breeds of goat that produce more cashmere than others, and those living in colder climates will naturally benefit from a healthy thick layer of downy undercoat.
Most commercial cashmere nowadays is produced in Northern China, other large producers include Mongolia, Afghanistan, and Tibet. The name cashmere comes from Kashmir which is now a disputed area on the borders of Pakistan, India and China but historically referred to as the high valley between two mountain ranges of the Himalayas.
It has been produced in Kashmir, Mongolia, and Nepal for thousands of years, with references to woollen shawls appearing in texts as far back as the 3rd century BC. There is a popular belief that it was during the 15th century that the then ruler of Kashmir, Zain-ul-Abidin, founded the wool industry in his country by bringing in weavers from then Turkestan, a historical region of central Asia. Other stories talk of another king of Kashmir, Sultan Qutubdin, won over by the fineness and durability of a gifted pair of cashmere socks which saw him establish the wool industry. During the 18th and 19th centuries, Kashmir had a thriving business of producing cashmere shawls, which the region is still renowned for, although politics and border disputes have hindered the industry.