The 1st Swiss Regiment () was a Swiss mercenary line infantry regiment in the French Imperial Army during the Napoleonic Wars. During the expansion of the Imperial Army in 1803, Napoleon decreed the formation of four Swiss mercenary regiments, one of these later becoming the famed 1st Swiss. After a short time serving in Southern Italy, notably serving at the Battle of Maide, the 1st Swiss were sent to Poland for the impending Invasion of Russia. During the invasion, the regiment remained in the reserve, but served with honour, notably at the Battles of Polotsk and later the crossing of the Berezina. After retreating from Russia, elements of the regiment served during the minor campaigns until May 1814. The regiment was then reformed under the Bourbon restored monarchy, and continued into the Royal Guard until its final disbandment in 1830.

Formation On 27 November 1803, authorised articles were signed in which a new Swiss infantry regiment was to be created. However, it was not until March 1805, just before the Ulm Campaign, that the new French emperor, Napoleon, ordered the reorganisation of the Swiss troops by imperial decree. The remaining three Swiss Demi-brigades, which were the result of the merger of the original six Swiss demi-brigades of the Helvetic Legion. The men of these remaining small units were merged to form the new 1st Swiss Regiment, formed by imperial decree on 15 March 1805. The 1st Swiss Demi-Brigade was based in La Rochelle, where it was dissolved on 11 May 1805 to provide the 3rd Battalion of the new regiment. The 2nd Swiss Demi-Brigade formed the 4th Battalion a month later when it was based in Livorno. The 3rd Swiss Demi-Brigade was split, sourcing the personnel for the 1st and 2nd Battalions on 5 July 1805 while in Bastia, Corsica.Greentree & Campbell, pp. 30–31Smith, Napoleon's Regiments, pp. 216–217Dempsey, pp. 593–601Dempsey, pp. 179–183

Napoleon took pains over their formation, demanding that the French rather than the Swiss authorities select officers and personnel appointing those above the rank of major. He also had to approve all Grenadier Company (Compagnie des Grenadiers) officers, from names put forth by the Colonel-General of the Swiss (a French appointment, held in 1808 by Maréchal d’Empire Jean Lannes). To ensure that the Swiss Confederation did not evolve military institutions that would attract volunteers away from his Swiss regiments, Napoleon forbade developing Swiss general staff academies and limited the home forces to a self-defence militia of no more than 20,000 men.

Though the majority of the recruits for the new regiment came from the now disbanded Swiss demi-brigades, the battalions of 1st Swiss Infantry Regiment were now spread out between Northern Italy, Corsica, and Elba was not declared fully operational until 4 July 1806 – and even then, with only 2,887 men, to be increased by piecemeal arrivals from Switzerland over the following months.

War of the Third Coalition In 1805, according to regimental records, parts of the regiment was embarked on the Mediterranean Squadron's ships at the Battle of Trafalgar, where one officer was wounded. By mid-1805, the regiment was consolidated within the new Kingdom of Italy with the Staff and 1st Battalion based at Bastia, the 2nd Battalion on Elba, the 3rd Battalion near Modena, and 4th Battalion in Genoa.

4th Battalion

The 4th Battalion under Louis Clavel was detached to the Right Wing Division of the Army of Italy and fought at the Battle of Castelfranco Veneto where three officers were wounded. During the remainder of the campaign, the battalion was composed of 666 troops.

The 4th Battalion was still in the Right Wing, being involved in the Invasion of Naples under General de Division Jean Reynier, a fellow countryman. Their participation in the invasion was well noted, especially at the Battle of Maida, where the story of the Swiss is not as well known as their British victors.

Maida Towards the end of the battle, the French right-wing broke, and because the British mistook the 1st Swiss as the British De Watteville's Regiment; because of the almost identical uniform; the 78th (Highlanders) Regiment of Foot allowed the 1st Swiss to advance within very close range. The 1st Swiss then fired a volley and caused mass casualties in the regiment and increased confusion as the 78th thought this was a friendly fire incident. When the 78th realised their mistake, it was too late, and they began to retreat. The 78th then reformed and pushed back the 1st Swiss towards Dignoet's Brigade, where the 1st Swiss began to retire slowly and in good order.

Following the end of the battle, the 1st Swiss were grouped with the 23rd Light Infantry Regiment, and 9th Mounted Chasseurs along with four 6-pounder cannons to cover the army's retreat. At the battle, the 1st Swiss with 600 men engaged, lost 82 men killed or wounded and 55 taken prisoner. However, these returns are disputed as official British returns show some 102 Swiss prisoners of war after the battle. Among the officers, one was killed, one mortally wounded, and four wounded, with Chef de Bataillon Clavel included amongst the latter. He was rescued by the British De Watteville's Regiment, who organised his exchange for French prisoners. However, his wounds were very severe, and he ultimately died from their effects on 23 July 1808, over two years after they were inflicted.

Calabria

Following the disaster at Maida, the populace of Calabria (a fiercely pro-Bourbon province of the newly created Kingdom of Naples) rebelled against King Joseph Bonaparte. On 5 July 1806, the regiment and the remainder of Reynier's army were still retreating when it came upon the village of Marcellinara, desperate for food and water. To the amazement of the French, they were welcomed enthusiastically by the populace shouting "Long live the English" and "Death to the French", once again because they were mistaken for British soldiers. However, this comical situation ended tragically, when the Swiss opened fire on the populace, and the village was sacked.

3rd Battalion The 3rd Battalion was originally also scheduled for inclusion in the Army of Naples. Still, it was diverted to assist in the suppression of a significant uprising by Italian peasants in Parma, Piacenza, and the Trebbia Valley in January 1806. The incident, involving upwards of 20,000 inhabitants driven to insurrection by the abuses of the occupying French forces, gave the Swiss a taste of the type of action they would encounter again in Calabria. The 3rd Battalion finally made it to Naples in September 1806, followed shortly thereafter by the 1st and 2nd Battalions. The 4th Battalion was held back at Naples because it still had not made good the losses suffered at the Battle of Maida, but the other three battalions were plunged into the fighting in 1807 as the French attempted to pacify Calabria once and for all.

Calabrian Campaign Throughout the Cambrian campaign, the 1st Swiss proved themselves as a distinguished anti-partisan unit. The 1st Battalion even managed to distinguish itself at the crucial Siege of Cotrone at the end of June, when two of its offices earned the Legion of Honour. Because of its reliability in the field, Joseph Bonaparte of the new Kingdom of Naples conceived a plan of transferring the 1st Swiss Regiment into its own nascent Neapolitan Army and even persuaded Napoleon to permit that. He negotiated a convention to that effect in December 1807. Yet, it was not ratified by all the Swiss cantonal governments until June of the following year, by which time Joseph had already accepted a transfer to the throne of Spain. His successor, King Joachim Murat, decided it would be an insult to his new subjects to allow foreigners in his army, so the plan was never implemented.

However, the new King did not object to the regiment's continued use in the vanguard of his military endeavours. The Grenadiers, Voltigeurs, and battalion artillery of the regiment were consequently included in the elite force that stormed the island of Capri in October 1808 and captured the British garrison commanded by General Sir Hudson Lowe. The following year, the 1st Swiss also played a prominent part in defending Capri and nearby coastal targets. The 1st Swiss suffered some combat casualties as a result of these endeavours, but the real enemy turned out to be the malaria that was endemic around the Bay of Naples, which killed nearly 800 men (including some who became so depressed by the disease that they committed suicide).

In 1810, the 1st and 2nd Battalions, the elite companies (Grenadiers and Voltigeurs) of the 3rd and 4th Battalions, and the regimental artillery company were all assigned to the force that King Joachim Murat concentrated at the toe of Italy in August to launch an invasion of Sicily. That plan was abandoned after two Neapolitan battalions made their way to the shores of Sicily and were captured en masse, and the various components of the 1st Swiss were dispersed to a variety of garrisons and duties in lower Calabria. Finally, in July 1811, the 1st Swiss received a reprieve from its hard labours in the form of a summons to re-join the main French armies after an absence of over five years.

Invasion of Russia

Preparations As Napoleon's new Grande Armée assembled in the eastern parts of the Duchy of Warsaw, the need for Swiss troops became apparent. Napoleon even said, "We must pay serious attention to the Swiss regiments". He went on to call for a major effort to recruit the regiments up to strength and bring about their organisation. As a result, over the next year's course, the regiments were gradually reassembled, and each received a new regimental artillery company. Each artillery company composed of two 3-pounder mountain field cannons.Dempsey, pp. 625–646

The initiative also resulted in a re-negotiation of the convention governing the four Swiss regiments, after Napoleon decided that he preferred four smaller full-strength regiments rather than four larger ones which never came close to their prescribed establishment. Therefore, the overall Swiss contingent was reduced to 12,000 men and changed the composition of each regiment:

Each Regiment to have a Regimental Staff, 3 x Active Battalions, 1 x Depot Demi-Battalion and 1 x Regimental Artillery Company (as described beforehand) Each Active Battalion will consist of: 1 x Grenadier, 4 x Fusilier, and 1 x Voltigeur Companies of 140 men each

Under Article 9 of the new conventions, the Swiss government was required to produce a steady stream of 2,000 replacements a year to keep up with attrition, with an extra 1,000 per annum required in case of the outbreak of war in Germany or Italy.

By 1812 following the reorganisations of the previous year, the 1st Swiss were reorganised into two active battalions with a total strength of 2,103. According to Dempsey, only two battalions were active at this time, though the regiment was actually the most numerous, with the 2nd Swiss Regiment being just behind in three battalions with 1,822 troops. By the time of the beginning of the Invasion of Russia, all Swiss regiments were grouped for the first time in Maréchal d’Empire Nicolas Oudinot's II Corps. the 1st and 2nd Swiss Regiments were grouped into General de Brigade Jacques Savettier de Candras's Brigade, which in turn was paired with Coutard's Brigade (3rd Swiss and 128th Line) and Amey's Brigade (4th Swiss and 3rd Provisional Croats) in General Merle's Division.