Founder and commanding officer of a regiment of Swiss mercenaries. Born in Saint-Sulpice, Switzerland, the son of a merchant, Charles Daniel de Meuron gave up his apprenticeship in Strasbourg to enlist in the Hallwyl regiment at the age of 17, and fought in the West Indies during the Seven Years' War. After the Hallwyl regiment disbanded in 1765, he served a further 16 years in the Swiss Guard.

Although he was a decorated officer, his prospects of military promotion were restricted because he was a Protestant. He was also disappointed when nothing came of his project for a colony in the Guianas. His fortunes changed in 1781, when the French minister in Holland, Comte d'Affry, recommended him to the Dutch East India Company, which was in search of a mercenary regiment to protect the Dutch colonies from invasion by the British. It was particularly worried about its supply base at the Cape, which since 1652 had been provisioning its ships on the voyage to India.

De Meuron raised a private army under his name in the principality of Neuchâtel; ten companies of 100 soldiers, most of them Swiss, all Protestants. Once formed, the Meuron Regiment left for Cape Town, where for the next few years it shared garrison duties with the Pondicherry Regiment, which had been sent by the French to support their Dutch allies. Tensions ran high during the regiment's short period at the Cape: Duels were fought between the regiments; De Meuron quarrelled with Cape officials; desertions, mutiny, and other internal divisions plagued the regiment.

Its troubles were primarily the consequence of delays on the voyage out. While waiting for the order to depart at their depot in Ile d'Oleron, nearly a third of the troops died from an outbreak of smallpox. They were replaced by French convicts, a decision that caused major disciplinary problems for the future. To make matters worse, by the time it was ready to set sail the fleet had missed the most favourable season for voyaging and took more than five months to reach the Cape. Reduced to half rations midway through the journey, hundreds of troops came down with scurvy, and more than a hundred died.

Soon after the fleet landed in Cape Town, in January 1783, the first desertion conspiracy was discovered. Rumours circulated that the plotters, all of them former convicts from Paris jails, had been tortured with burning candles, and that one of them had died as a result. Although the allegations of torture were never proved, they were hard to dispel and caused de Meuron, who had a reputation as a strict disciplinarian, great embarrassment. Nor did the threat of severe punishment do anything to stem the desertions, and undoubtedly many escapees were absorbed into Cape society. Other soldiers from the regiment, found guilty of theft and other, mostly petty, crimes, ended up serving long sentences of hard labour on Robben Island. To compound de Meuron's problems, certain senior officers resigned in protest against his overt favouritism in matters of promotion, and others, hoping to have their commander removed for misadministration and cruelty, complained to the Cape authorities. Appointing his brother Pierre-Frédéric as his successor, De Meuron returned to Europe in 1786 in an effort to repair his damaged reputation and to resolve the question of arrears, which had become a further cause of unrest.

Before the situation disintegrated completely, the regiment was relieved by German mercenaries and redeployed to Ceylon, although at least 18 of the Meuron soldiers remained as colonists. Profiting from the turmoil caused by the French Revolution, the British were again attacking the Dutch colonies. In 1795 they stormed Ceylon, taking two companies of the Meuron regiment prisoner. After a weak attempt at defence, Holland surrendered the colony, and shortly afterwards was itself invaded by French troops. The prince of Orange, who was Head of the Dutch East India Company, was forced to place himself and his family under the protection of the George III, King of England.

These events marked the start of negotiations between de Meuron and the British Ambassador to transfer the regiment into the British Army. Under the terms of the final agreement, signed in 30 March 1795, de Meuron was paid £4000, and he and his brother were given the rank of General. In India, the Meuron Regiment participated in the Mysore Campaign of 1799, under the command of Lt-Colonel Arthur Wellesley, later the Duke of Wellington, which ended in the seizure of Seringapatam, a decisive victory for the British in their conquest of the Indian subcontinent. Shortly afterwards, de Meuron returned to Neuchâtel, leaving Pierre-Frédéric once more in command of the regiment.

The regiment remained in India until 1806, when, decimated by the Indian campaigns, it was returned to England for reinforcement and then dispatched to the Mediterranean, where it was assigned to garrison duties, and fought in the Peninsular War. It was then sent to Canada to fight against the Americans in the War of 1812. The Meuron Regiment was disbanded on 24 September 1816.

De Meuron had been a passionate collector since childhood and continued to collect as a soldier. There are no records of him ever making collecting trips in South Africa. It is probable that he had local objects and specimens brought to him, just as those he desired from India, China and Ceylon were delivered on the ships calling at False Bay on their journey homeward. While at the Cape, he is known to have sent plants to Marie-Antoinette, through a mutual friend, and on his return to Europe in 1786 visited the gardener of the Trianon at Versailles. Before leaving for India to oversee the transfer of his regiment, he donated his cabinet to the town of Neuchâtel, where it formed the basis of the Musée d'Histoire Naturelle and Musée d'Ethnographie. The history and contents of his collection are described in Roland Kaehr's Le mûrier et l'épée: le Cabinet d'histoire naturelle de Charles Daniel de Meuron et l'origine du Musée d'ethnographie à Neuchâtel (2000). He is commemorated botanically by Erica meuronii Benth.