The valley of the River Spey and its tributaries has long produced whisky, but the modern shape of Speyside — with more working distilleries per square mile than anywhere else in the world — was formed largely between 1823 and the end of the 19th century.
Before the Excise Act of 1823, distilling in the Highlands was widely undertaken outside the law. The Spey valley, with its clean water, plentiful barley and remote glens, was well suited to illicit stills. Some later legal distilleries stand on the sites of these earlier hidden operations.
The Excise Act made licensed distillation economically viable for the first time. The Glenlivet, licensed in 1824 by George Smith, is often cited as the first Highland distillery to take up the new terms, and its example was followed rapidly across Speyside.
The Spey is not a boundary but a spine; the distilleries lean into it on either side.
A second wave of expansion came with the arrival of the railway. The Strathspey Railway reached Aviemore and beyond in the 1860s, and the Speyside line opened new markets and eased the transport of coal and barrels. Distilleries such as Cragganmore, Glenfarclas, and later Cardhu and Glenrothes were built or expanded during this period.
The Victorian golden age closed abruptly with the Pattison Crash of 1898, a spectacular business failure that ended two decades of speculative expansion. Some distilleries never reopened; others were mothballed for generations.
The 20th century brought further contractions and consolidations, but also the reopening of many silent stills. Today, Speyside contains more than fifty working distilleries, and its whiskies — often characterised as elegant, fruity and, in the case of the great sherried houses, richly flavoured — have shaped global perceptions of what single malt can be.