Although the higher part of the canton of Neuchâtel rises to about 1000m above sea level, most of its towns and villages lie in shallow valleys, as signified by the word “Chaux” (meaning “high valley” in local patois) found in several place names.  The villages of La Sagne and Les Ponts-de-Martel lie in a valley whose central plain was essentially a peat marsh, and both “sagne” and “martel” mean marshland. The name "Le Locle" comes from the Celtic word "loch" or lake, as the valley where it is situated was once filled with water.  These valleys are surrounded by mountain tops covered in pine forest which earned the region its old patois name “Les Noires Joux”.

The upper part of the canton of Neuchâtel was not settled as early as the more accessible lakeshore.  The first mention of Le Locle is in an obituary of 1151, referring to a gift of land made by Renaud de Valangin and his son Guillaume to the recently-founded monastery of Fontaine-André at La Coudre.  This apparently pious gesture probably served a double purpose, as the lords of Valangin were anxious to encourage the colonisation of a largely empty frontier region.  Under the monks’ impulsion, land was cleared, and families gradually started to settle the region.  In the 13th century, the lords of Valangin bought back their rights to the land, and implemented a more active programme of colonisation, notably by offering social advantages to the pioneer settlers.  In 1372, Jean d’Aarberg signed a charter freeing the inhabitants of Le Locle and La Sagne, and proclaiming them “franc-habergeants” or free men, with the right to dispose of their own land.  Over the next century, more rights were acquired (generally in return for payment), to such an extent that in 1480, the region was known as “Le Clos de la franchise”.  From 1502, the free men of Le Locle and La Sagne could even obtain the socially-desirable position of “bourgeois” of Valangin.

At the end of the 14th century, 31 adult males held land under the lord of Valangin at La Sagne, and 28 at Le Locle.  In 1416/17, there were 50 hearths in the parish formed by the two villages, and by 1531, this figure had grown to 268 hearths, including 145 for Le Locle alone.  Baptismal records show that this population explosion was not the result of migration from elsewhere, but of an extremely healthy birth-rate! 

By the end of the 15th century, Le Locle and La Sagne were large enough to form two separate parishes.  Les Brenets became a parish in its own right in 1512, and La Chaux-de-Fonds in 1550, although a chapel existed there as early as 1528.  The Reformation was brought to the canton of Neuchâtel by the French preacher Guillaume Farel in 1530, but at first the new doctrine was steadfastly resisted by church and secular leaders in Le Locle and La Sagne.  However, popular pressure from both sincere believers and those who saw an opportunity for ridding themselves of the heavy dues imposed by the Catholic church brought about a peaceful acceptance of the Reformation in 1536.

For many years, the villages of the Neuchâtel mountains were purely agricultural, but gradually the increasing population forced the inhabitants to look for additional sources of revenue.  Millers, carpenters, blacksmiths and other craftsmen began to appear alongside the self-sufficient farmers, often using the natural force of the rivers Doubs and Bied to drive their tools.

In 1584, Marie de Bourbon  bought the rights to Valangin, and the Neuchâtel mountains came under the control of the House of Orléans-Longueville, where they would remain for over a century.  As the neighbouring Franche-Comté region was then in the hands of Spain, the area suffered from tensions between the two European powers, particularly during the Thirty Years War when France’s Swedish allies occupied the Morteau valley.  However, the Peace of Westphalia restored calm in 1684.

In the 17th century, Le Locle was still the most important town in the Neuchâtel mountains, with a population of about 2,300, and this period saw significant economic development in the region.  New industries were brought by French refugees after the revocation of the Edict of Nantes in 1685, notably lace-making, which provided a welcome supplement to farming families’ income during the winter months.   The watchmaking industry was still in its infancy, following the installation of Daniel Jeanrichard in Le Locle in 1705, but it would soon become a major force, with emblematic figures such as Jacques-Frédéric Houriet (1743-1830), Sylvain Mairet (1805-1890) and Frédéric-William Dubois (1811-1869). 

In 1752, there were 460 watchmakers in the Neuchâtel mountains and the Val-de-Travers, and by 1791 this figure had risen to 3,500.  Other crafts thrived too, as enamellers, lapidaries, gilders and precision toolmakers turned their attention to the demands of the watchmaking industry, and the local workforce was reinforced by migrant labour.

La Chaux-de-Fonds originally just offered seasonal accommodation to farmers from the Val-de-Ruz who brought their cattle to graze there in the summer, but the growing population of the Neuchâtel mountains caused the village to grow sufficiently to have its own local administration by 1656.  With the arrival of the lace and watchmaking industries, the village became a thriving town, rivalling Le Locle in size and importance. 

Close contact with neighbouring France meant that sympathy was strong for the Revolution and republican ideals in the region.  “Subversive” literature from outside the country was outlawed by the Neuchâtel government, but everyday contact with traders, soldiers and later French refugees naturally continued to influence local opinion, particularly in the industrial centres of Le Locle and La Chaux-de-Fonds.  In 1792, over 1,000 inhabitants of the Neuchâtel mountains crossed the border to celebrate the burial of the French monarchy at Morteau, and some even swore allegiance to the French Republic.  Two patriotic societies were formed at Le Locle and La Chaux-de-Fonds, and red “liberty caps” were distributed to sympathisers, leading to confrontations with those who remained faithful to Prussia.  In the mountains, only the agricultural valley of La Sagne remained generally sympathetic to the monarchy, but heavy dissuasive force from the Neuchâtel government led to the disbanding of the patriotic societies, and the departure of over 300 families from Le Locle and La Chaux-de-Fonds for Besançon in 1793.

In 1798, Switzerland was invaded by French troops, but Neuchâtel was left untouched because of its links to Prussia.  Following the defeat of Austria at the battle of Austerlitz in 1806, Friedrich-Wilhelm III ceded Neuchâtel to Napoleon, who placed it in the hands of marshal Berthier.  Berthier never actually visited his principality, but during his brief reign major roads were built connecting La Chaux-de-Fonds and the valley of La Sagne to Neuchâtel.  Following the defeat of Napoleon, Neuchâtel was reclaimed by Prussia.  However, the principality had by now drawn much closer to the Swiss Confederation, and following diplomatic negotiations, it was recognised as simultaneously Prussian principality and Swiss canton in September 1814.

Republican uprising of 1848.

The republican movement had grown in importance, and in 1831 a first attempt was made to overthrow the government.  It was easily defeated, but split the canton irrevocably into royalists and republicans, with no compromise possible.  The abdication of Louis-Philippe in France in February 1848 provided the final impulsion to the republicans, who gathered in La Chaux-de-Fonds and started negotiating with the authorities. 

On 29 February, patriots in Le Locle hoisted the Swiss flag and seized control of the town, declaring Neuchâtel a republic: a declaration rapidly echoed throughout the mountains.  The following day, republican troops marched from La Chaux-de-Fonds to Neuchâtel under the leadership of Fritz Courvoisier, and took control of the castle without bloodshed, the government having wisely decided to oppose no resistance.  A provisional government was installed under Alexis-Marie Piaget,  and the new status of Neuchâtel was rapidly recognised by most European powers.  An attempted counter-revolution in 1856 was a failure, and Prussia finally renounced her rights over the canton in 1857.

Under the new republican constitution, elementary schooling became obligatory, and the 19th century saw the construction of schools and educational institutions throughout the region.  The first railway in the canton was built between Le Locle and La Chaux-de-Fonds in 1857, and extended to Neuchâtel in 1860, reducing greatly the isolation of the mountain towns and villages.  Industry gradually became mechanised, and large factories replaced the multitude of small workshops.  La Chaux-de-Fonds grew rapidly to become the largest town in the canton, partly due to the arrival of Swiss-German migrants.

In 1870, the Neuchâtel mountains found themselves uncomfortably close to the war between France and Germany.  Arms intended for France were confiscated at Les Verrières, and over 12,000 Germans and Swiss fled France through the canton at the outbreak of hostilities.  Troops were mobilised to defend the Neuchâtel border, and when General Bourbaki’s army was routed in February 1871, the canton was authorised to take in the defeated soldiers at Les Verrières: the first example of international aid by Switzerland.

Troops were again mobilised to close the border during both World Wars, and recession hit hard in the Neuchâtel mountains in the 1920’s and 30’s.  The watchmaking industry was restructured, and other industries gradually appeared.  Today the region no longer relies on a single industry, although the clock and watch museums at La Chaux-de-Fonds and Le Locle bear witness to its lasting importance.  In their high valleys surrounded by pine forest, the towns, villages and isolated farms of the Neuchâtel mountains combine a modern outlook with 850 years of tradition.