The Western Isles are also known as the Outer Hebrides, and stretch from the Butt of Lewis in the north to Vatersay in the south - a distance of 130 miles. The electorate is less than 23,000 - about half that of most Scottish constituencies.
Lewis is the largest island, but others include Harris, the two Uists (North and South) and Benbecula, from where Bonnie Prince Charlie sailed "over the sea to Skye".
Crofting, fishing, limited tourism and cottage industries are the basis of the local economy, along with the manufacture of Harris tweed - the islands' most famous export. The Isles are remote from the mainland in culture as well as distance. Some 68% of inhabitants are Gaelic speakers. The Gaelic name for the Western Isles is Na h-Eileanan Siar.
This seat has historical significance for both the SNP and the Labour party. Malcolm K Macmillan took the seat for Labour in 1935, making it the first non-urban/industrial seat that the party had won. He held it until 1970 when he was defeated by the SNP’s Donald Stewart. This was the first time the SNP had won a seat at a general election.