Charles De Geer
A Swedish magnate and meticulous scientist who meticulously cataloged insects while running a vast ironworks empire.
1720–1778 (age 58)·Swedish entomologist, industrialist and civil servant·Birthday: January 30
Biography
Charles De Geer lived a life of parallel grandeur: one in the soot and roar of the forge, the other in the silent, precise world under a magnifying glass. Inheriting the massive Lövstabruk ironworks as a young man, he became one of Sweden's wealthiest industrialists, a baron overseeing a complex community of workers. Yet his enduring legacy was forged in his study. A passionate entomologist from childhood spent in the Netherlands, De Geer devoted his leisure to the microscopic study of insects. His life's work, the lavishly illustrated 'Mémoires pour servir à l'histoire des insectes', was a monumental seven-volume treatise that rivaled the earlier work of the French master Réaumur. De Geer wasn't just a collector; he was a sharp observer of insect behavior, anatomy, and life cycles, describing hundreds of species for the first time. He embodied the 18th-century ideal of the gentleman-scientist, using his fortune to fund a pursuit that brought meticulous order to the smallest corners of the natural world.
#1 When Charles Was Born
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Charles's Life & Times
The world at every milestone
1720Born
1725Started school
1733Became a teenager
1736Could drive
1738Could vote
1741Turned 21
1750Turned 30
1760Turned 40
1770Turned 50
1778Died at 58
Key Achievements
- Published the seminal seven-volume work 'Mémoires pour servir à l'histoire des insectes' between 1752 and 1778.
- Described and classified numerous insect species for the first time, with many still bearing his taxonomic names.
- Successfully managed and expanded the Lövstabruk ironworks, a major center of Swedish industry.
- Was elected a member of the Royal Swedish Academy of Sciences in 1739, at age 19.
- Built a vast and renowned natural history collection, particularly strong in insects.
Did You Know?
He was born in Sweden but spent his formative years (ages 4 to 18) in Utrecht, Netherlands, where he began studying insects.
His cousin and fellow entomologist, Carl Linnaeus, named the moth genus *Degeeria* in his honor.
He corresponded with many leading European scientists of his day, including Linnaeus and Réaumur.
His personal library and collections were so vast they required a specially built annex to his mansion.
“The wings of this moth are covered in the most exquisite minute scales.”
