How prominent was Leeuwenhoek's family?

Leeuwenhoek is often portrayed as an uneducated merchant whose curiosity and diligence let him rise from obscurity to find an honored and secure place in the history of science.

The question then becomes, where did he find the time?

• How did he buy the time without family wealth like that of Christiaan Huygens or most of the members of the Royal Society?
• How did he manage to leave a substantial estate to his daughter?
• How did he accomplish anything without a formal university education?

In the 1600's, such an education meant reading and writing Latin. It meant a degree from the university in Leiden or perhaps one in France. The leisured life of the landed gentry or even the cities' regents meant knowing French. However, none of Leeuwenhoek's ancestors seem to have had a university education or to have known other languages. Likewise, Leeuwenhoek went through the apprenticeship system to become a cloth merchant. At least early in his career, he knew no language other than Dutch.

1729

His first biographer, Boitet mentioned his descent from very deftige and eerlijke parents in Beschryving der Stadt Delft (p. 765). In Sewel's 1735 dictionary, deftig means grave or magnificent and eerlijk means honest or honorable.

1875

His relative Haaxman repeated Boitet in De Ontdekker der Infusorien (p. 7).

Haaxman mentioned four families -- Hogenhoek, Bleiswijk, Swalmius en Mathenesse -- of which only the first can be documented as being in Leeuwenhoek's direct maternal ancestry. In some letters late in life, Leeuwenhoek addressed to the city's anatomist Abraham van Bleyswijk and referred to him as neef, literally nephew as in sibling's child, but also a term of familiarity for young males of any degree of distant relation, much as cousin is used in English. Leeuwenhoek was related distantly by marriage to the Bleiswijk family. His second wife was a Swalmius. The Mathenesse are a Rotterdam family; none are listed in the Delft birth, marriage, or death records.

1932

His English-language biographer Dobell summarized in Antony van Leeuwenhoek and his “little animals” (p. 21) the evidence as he saw it:

Leeuwenhoek's mother was Margaretha, daughter of Jacob Sebastiaanszoon Bel van den Berch, a Delft brewer. She belonged to a good family, and was related to other Dutch families of equally good standing. The brewers then, as now, were no inconsiderable folk in Holland; and it thus seems clear that any claims which our Antony may have to gentle birth must rest upon his mother. ... Antony was a true Hollander of decent though not of aristocratic descent — a child of fairly well-to-do tradespeople.

In a footnote, Dobell mentions without any further corroboration the four families that Haaxman listed.

1950

His Dutch-language biographer Schierbeek, in his two-volume biography (pp 14, 15), reviewed the assertions of the previous biographers, including erroneous speculation about Jewish ancestry that had appeared in some 19th century articles. Schierbeek let the information stand without making any further inferences.

1952

A long, exhaustively footnoted article by van Seters -- Leeuwenhoek's afkomst en jeugd (Leeuwenhoek's origins and youth) -- related all the then-known archival data. It concentrated on Leeuwenhoek's maternal line. While van Seters did not provide a pithy summary, he made it clear that Leeuwenhoek was descended on his mother's side from a long line of Delft's most influential citizens.

1959

The last full biography was Measuring the Invisible World (cover, left), the 1959 one-volume condensation and English translation of Schierbeek's two-volume work. Maria Rooseboom wrote the opening biographical chapter. She concluded (p. 14):

It also seems probable that Antoni's mother came from a better class family, for her grandfather and several of her great uncles were merchants of considerable importance. Her father was the only one of a large family who became a brewer, and since this was at a time when the brewing industry was on the decline, we may suppose that, after his death in 1615, his seven children did not live in ease and abundance. It seems therefore as if Leeuwenhoek's mother belonged to the least prosperous branch of a family which was generally highly respected, and from which had come many City Fathers.

From what van Seters documented, Rooseboom's supposition does not seem well founded. The decline of the industry says nothing about an individual brewery, which may well have profited from the winnowing of competition. What we know about her father Jacob's siblings does not justify "least prosperous branch". Van Seters provides evidence that the brewery may well have been supplemented by a business selling cloth.

Since 1959

Many articles and books have provided summary biographies. They are interested more in Leeuwenhoek's science than in his life, and none has added any documented evidence that would expand what these earlier biographers knew about his ancestry.

In the family sections and the Delft government section of this web is documented information about Leeuwenhoek's ancestors. Those on the maternal side whose lives are best documented had for centuries been among the regent families ruling Delft. Had Antony been born into a regent family -- a van den Berch or Hogenhouck -- he may well have followed his ancestors onto the Veertigraad. He would have been a magistrate himself rather than a paid official who provided services to them.

In short, when the city administrators, all regents from deftige and eerlijke families, appointed Leeuwenhoek to his various posts in city government, posts that required a trustworthy man, they were appointing one of their own.