Jan van Leeuwen

Patronymic: 
Claes

Leeuwenhoek's niece's husband.

Leeuwenhoek's sister Catharina married Claes Jans van Leeuwen. Their daughter Rijckje (1656-1735), Leeuwenhoek's niece, married Jan van Leeuwen, who was later steward to the Russian Czar. This Jan Leeuwen may well have been the one to whom Leeuwenhoek addressed Letter 109 of 1697-09-03 (AB 187).

The letter could, however, have been addresed to Rijckje's brother Jan van Leeuwen, living in Rotterdam and through whom Leeuwenhoek had the Royal Society ship packets.