Klaas married Wopkje Dirks on 23 Nov 1755 in Hemelum, Friesland, Netherlands. Wopkje was born in 1735 in Hemelum, Friesland, Netherlands; was christened on 15 May 1735 in Hemelum, Friesland, Netherlands. [Group Sheet] [Family Chart]

1. Claas Clases was born in 1758 in Hemelum, Friesland, Netherlands; was christened on 3 Sep 1758 in Hemelum, Friesland, Netherlands.
2. Claas Clases was born on 10 Aug 1761 in Hemelum, Friesland, Netherlands; was christened on 16 Aug 1761 in Hemelum, Friesland, Netherlands.
3. Durk Clases was born in 1763 in Hemelum, Friesland, Netherlands; was christened on 9 Oct 1763 in Hemelum, Friesland, Netherlands; died in 1763 in Hemelum, Friesland, Netherlands.
4. Antje Clases was born on 19 Apr 1765 in Hemelum, Friesland, Netherlands; was christened on 21 Apr 1765 in Hemelum, Friesland, Netherlands.
5. Otte Klazes de Vries was born on 1 May 1768 in Hemelum, Friesland, Netherlands; died on 19 Mar 1838 in Workum, Friesland, Netherlands.
6. Durk Clases was born on 26 Mar 1771 in Hemelum, Friesland, Netherlands; was christened on 29 Mar 1771 in Hemelum, Friesland, Netherlands.
7. Willem Clases was born on 18 Jun 1774 in Hemelum, Friesland, Netherlands; was christened on 3 Jul 1774 in Hemelum, Friesland, Netherlands.
8. Zijts Clases was born on 16 Feb 1777 in Hemelum, Friesland, Netherlands; was christened on 2 Mar 1777 in Hemelum, Friesland, Netherlands.

Claas married Antje Roelofs on 18 Jan 1722 in Hemelum, Friesland, Netherlands. Antje was christened on 23 May 1697 in Hemelum, Friesland, Netherlands. [Group Sheet] [Family Chart]