In the late Middle Ages, what is now the Dutch province of Fryslân was divided by an estuary that was dubbed ‘Middle Sea’ in a contemporary chronicle. By 1500, most of it had silted up. The remaining wetlands were reclaimed when a consortium of fourteen investors built a dike around it in 1505. During the following decades, hundreds of settlers from all over the northern Low Countries moved in. Among them were four sons of a tenant farmer from Sassenheim, a village near Leiden in what is now the Dutch province of Zuid-Holland. In 1566, their sons went back to Sassenheim to establish their pedigree. The local sheriff was more than accommodating and even suggested that the family, which had recently adopted a coat of arms, was of noble descent.

                 The arms blazoned in the sheriff’s affidavit of 1566 indeed had traits of that of an old Dutch baronial family: the Lords of Wassenaar, whose patriline had become extinct in 1525. The appropriation of their crest gave status to the second generation in Fryslân. Before long, some scions of this family even adopted ‘Wassenaar’ as their surname. The earliest armigerous branch, however, was recorded in tomb inscriptions and other sources as ‘Bonte’ or ‘Bonteman’. The origin of that surname is unknown, but some ‘Bonts’ or ‘Bontes’ have been on record in Leiden, and a coat of arms very similar of the one adopted by the family in Fryslân is known to have been depicted in the late Middle Ages on a stained-glass window in the church of St Peter’s at Leiden.

                 In 1907, an 18th-century copy of the affidavit of 1566 was retrieved from the estate of a descendant of Klaas Willems, one of the four brothers who went from Sassenheim to Fryslân. A long discussion of his assumed noble ancestry ensued, culminating in the publication of a hefty genealogy in 1963. Even more than the sheriff in 1566, the author of 1963 elaborated on the noble roots of the ‘Frisian Wassenaars’, even linking them to the Royal House of Orange-Nassau. These pretentions were discredited half a century later, when a DNA comparison was conducted between J.W.F. baron van Wassenaer and two agnatic descendants of Klaas Willems. Both ‘Frisian Wassenaars’ turned out to be each other’s close kin, but unrelated to the friendly baron.

                 Among scholarly professionals, the ‘Frisian Wassenaar’ genealogy is considered generally reliable from the sixth generation onwards, in other words: from the early 17th century to date. Around 2000, much new material form archives in the western Netherlands became available, making rewriting of the first five generations of ‘Frisian Wassenaars’ highly desirable. Strictly speaking, the earliest documentary evidence for the family is a mentioning of their primogenitor as a neighbour to a fief near Sassenheim in 1479. The affidavit of 1566 mentions one earlier generation: one Steffen Huigs (‘Steven, son of Hugh’), but he has not been identified in any contemporary source from the Sassenheim area. According to a church register, one Stephanus filius Hugonis reportedly died in 1505/1506 in what is now a suburb of Amsterdam. He was also a priest and there are no known sources relating him to Sassenheim, so the patriline must end here.

                 In the following presentation of the first documented generations of these ‘Wassenaars’, the numbering of generations (in Roman numbers) and persons (in Arabic numbers) follows the genealogy of 1963. Some new persons have been added. Their Roman generation numbers are followed by a lower-case letter instead of a number. All given names and patronyms have been standardised according to the Frisian names thesaurus as published in 2014 on


See also the bibliography in K. Kuiken, Het Bildt is geen eiland. Capita cultuurgeschiedenis van een vroegmoderne polder in Friesland (Groningen and Wageningen 2013) 281-307 and the English summary on pp. 255-263 of that study. .

Introduction to the Frisian Wassenaars’ pedigree

By Kees Kuiken

Picture Wassenaar coat of arms