Charles De Geer (30 January 1720 – 7 March 1778) was an entomologist, industrialist, civil servant and book collector. He is sometimes referred to as Charles the Entomologist, to distinguish him from other relatives with the same name. Charles De Geer came from a prominent Swedish-Dutch family. Born in Sweden, he spent most of his childhood and youth in the Dutch Republic. At the age of 18 he moved back to Sweden and would spend the rest of his life there. Upon his return to Sweden, he took over the management of the ironworks of Lövstabruk. He was a successful businessman and with time became one of the richest men in Sweden, head of an early industry employing around 3,000 people. He had a successful civic career, became Marshal of the Court and was elevated to the rank of friherre (baron) in 1773.
De Geer had developed an interest in natural history and particularly entomology when he was still young. After his return to Sweden, his interest transformed into a serious scientific pursuit. He was elected a member of the Royal Swedish Academy of Sciences in 1739 and a corresponding member of the French Academy of Sciences in 1748. He published his main work on entomology, Mémoires pour servir à l'histoire des insectes, in French in eight volumes between 1752 and 1778. In it, he provided descriptions of the behaviour of over 1,400 insect species. In his writings, De Geer among other things brought the importance of insects as pollinators to the attention of the scientific community, and criticised the idea of spontaneous generation.
De Geer was also a book collector. He used his library for his research, but it contained books on many other subjects in several languages. Its sumptuous and rare works, including a collection of music scores, indicate that it was also intended as a way to raise De Geer's social status as an aristocratic collector. Since 1986 it belongs to Uppsala University Library, but most of it is still kept in situ in Lövstabruk, in the pavilion De Geer constructed to house the library.
Charles De Geer's father was Jean Jacques (or Jan Jacobus) De Geer, and his mother was Jacquelina Kornelia van Assendelf. His mother was Dutch, and he was a member of the prominent Swedish-Dutch De Geer family. His great-grandfather was Louis De Geer, founder of the Swedish branch of the family.
Charles De Geer married Catharina Charlotta Ribbing in 1743. He was the first member of the De Geer family to marry a Swedish woman. She came from an aristocratic family, and through the marriage Charles De Geer came closer to the royal family. Unusually for the time, his wife organised the inoculation of all their children against smallpox, for which she was later commemorated with a medal. The couple had eight children. Among these his son, also named Charles De Geer, became a politician, and his daughter Hedvig Ulrika De Geer was like her father also a bibliophile and an intellectual.
The family name is spelled with a capitalized De as the particle is not strictly a nobiliary particle, and Charles De Geer himself also treated De as an integral part of the family name.
Early childhood in the Dutch Republic
Charles De Geer was born on 30 January 1720 in Finspång in Sweden, but moved to the Dutch Republic when he was three years old. The family owned the estate of Kasteel Rijnhuizen outside Utrecht. His interest in natural sciences began when he was still living in the Dutch Republic. An anecdote claims that his fascination was born when he was given silkworms and could watch their metamorphosis. At the age of sixteen, he organised the garden at the family estate according to the principles of Joseph Pitton de Tournefort, kept pigeons and collected insects and butterflies. Coming from a wealthy family, he was privately tutored by Dutch physicist Pieter van Musschenbroek, law professor Christiaan Hendrik Trotz, and Swedish astronomer Olof Hiorter; he kept in contact with Musschenbroek through letters throughout his life. Pieter van Musschenbroek's brother Jan also constructed a microscope and other scientific instruments for the young Charles De Geer. He entered Utrecht University in 1738.
He was brought up speaking Dutch. His journal detailing the trip when he moved to settle in Sweden from Utrecht in 1738 is written in Dutch and so is the first library catalogue he compiled of his collections in Lövstabruk in Sweden, from 1738. The second catalogue, from c. 1750, is written in Swedish, with some remarks in French. After his return to Sweden he appears to have made conscious efforts to learn Swedish and integrate into Swedish society by spending some years in Uppsala (though without formally attending Uppsala University), and soon became fluent in Swedish. In a letter dated less than one year after his arrival in Sweden he addressed the Royal Swedish Academy of Sciences in Swedish and excused himself (according to the article about him in Svenskt biografiskt lexikon "rather unnecessarily") for any spelling mistakes.
Return to Sweden and management of Lövstabruk ironworks
At the age of ten, Charles De Geer inherited the estate of Lövstabruk in northern Uppland, in Sweden. The estate had belonged to an uncle, also named Charles, who through his will and testament left all his real estate as an entailed estate to Charles De Geer, bypassing two of his older brothers. Charles De Geer did not immediately gain access to the estates, however, due to his young age. Instead, his father assumed the guardianship, while delegating much of the every-day business to his eldest son (and Charles' older brother) Louis, who lived in Finspång in Sweden. Charles' father worked to secure investments in the Netherlands, where loans were cheaper to get than in Sweden, for the estate.
Lövstabruk (also spelled Leufstabruk, Löfstabruk) developed as an ironworks, rather than an agricultural estate; it forms part of a group of iron works in northern Uppland managed largely by Walloon immigrants to Sweden. Tracing its origins to the Middle Ages, it was developed by Charles De Geer's great-grandfather Louis De Geer into an early industrial complex. In the 18th century, it was the most important ironworks in Sweden, and at the time of Charles De Geer employed over 3,000 people. Upon the death of Charles' uncle, the estate was however in an economically precarious state. Lövstabruk had been burnt down by Russian troops in July 1719, during the Russian Pillage of 1719–1721 at the end of the Great Northern War, and the losses incurred then had not fully been recovered. The situation was such that the owner at the time considered abandoning it and moving back to the Dutch Republic.
In the years that followed, Charles' father and elder brother managed to stabilise the economic situation of the estate. In 1738, his father died and Charles moved from Utrecht to Lövstabruk, as planned, to be introduced to the running of the estate. Formally he was not to assume ownership of the estate until the age of 25, but already in 1741 he took over the management of the estate. He ran it until his death and though supported by skilful staff, he took a strong personal interest in it.
He was a highly successful businessman, and eventually became one of the richest people in Sweden. He expanded the estate greatly, partly by acquiring woodland which supplied fuel for the ironworks, and partly by acquiring other ironworks to get rid of competition. He also sold some estates his predecessors had bought, including Österbybruk which he sold to the brothers Claes and Abraham Grill of the Grill family, making considerable profits. In an instruction he left behind for his successor, De Geer stressed the importance of not putting too much trust in administrators and inspectors, not to fret over details too much, to maintain good relations with the clergy and the crown, and to treat the workers well.
Refurbishment of Lövstabruk and book collecting
After Löfstabruk had been burnt down by Russian troops in 1719, a new main building was built in the 1720s. When Charles De Geer acquired the estate, he enlarged and refurbished it. As an architect he employed court architect Jean Eric Rehn. Two wings were added to the main building and an aviary was built in the park in 1759. In 1765, the interior of the main building was also refurbished to designs by Rehn. Furthermore, two pavilions were built next to the main building, one to house the main library and the other the cabinet of natural history, working library and study of De Geer, respectively.