Jacobus, known as Koos, has been a great friend and inspiration to the editors of this website. At this writing he resides in Kloosterburen with his wife Bernarda.

Koos has provided much detail for the Halsema line in our genealogy database and has provided much of the information on Kloosterburen and especially its Catholic Church, St Willibrordus, which you can find on these pages.

Since 1998 Koos has been an inspiration to the editors of this website, he is our third cousin, and we are proud to call him our friend.

Thank you Koos! –halsema.org editors.