Harris Tweed has been produced in the outer Hebrides for hundreds of years. Originally it was woven on hand looms, with the weavers and their families completing all of the processes themselves, from shearing, spinning, weaving to washing the tweed. It was mainly used for their own needs. In the 1800's Harris Tweed started to be known internationally and nowadays it is sold all over the world.
Most Harris Tweed is now produced on modern double width looms for 3 mills on the Isle of Lewis. There are a few small producers weaving with the older single width Hattersley looms who rely on the mills for purchasing yarn and having their tweeds finished.
Harris Tweed is the only cloth that is governed by an act of parliament which defines it as:
"Handwoven by the islanders at their homes in the Outer Hebrides, finished in the Outer Hebrides, and made from pure virgin wool dyed and spun in the Outer Hebrides."
Quote from the Harris Tweed Authority web page www.harristweed.org
If you are interested in learning more about Harris Tweed then the Harris Tweed Authority web page has a wealth of information available.