I have de Jongh (spelled with the "h", like yours) ancestors, but they were back around 1600, in Gelderland.The spelling is that of an old Flemish family, which seems to have fled north to the safety of the Netherlands for religious reasons.I have yet to see a solid connection with the Gelderland line, and this is the first I've seen of a Frisian connection; but because of the spelling, I would keep these things in the back of my mind.The "Jonge" spelling is much more common and more recent.Here are some of my notes:
"On March 3, 1660 Albert Roosa, living in Herwijnen, conveyed half a tract of land as yet undivided between the heirs of Govert Ariensen De Jongh, in Hellouw ( a mile or so from Herwijnen) and again he pledged his interest in the estate of the late Adrian Meertensen De Jongh as security for the fulfillment of the contract. It is further proof that the wife of Albert was the daughter of Adrian Meertensen. The de Jongh family owned large fowler preserves in Hellouw in the 17th century."
"I have tried, so far in vain, to trace the origin of this De Jongh family back to the De Jongh family of Ghent and Bruges, where their arms were registered as early as 1280, one of the patrician families of Flanders. It is my belief, however, that we do spring from that origin, where the letter "h" in our name had its origin. The families of the name in Holland origin rarel;y used the letter "h". In Herwijnen, and elsewhere, these de Jonghs generally held official positions where they resided.
"The great grandson of ...Ds. Martinus Adrianuse De Jongh has quite a story on the family in "Navorscher", published in 1904... In that article, written by M. J. De Jongh, is described the physical characteristics of his forefathers as large and well-built type, keen-minded men, of zealous and crusading nature. Longevity he states also was common among them, and they had a fiery delivery as ministers. That corresponds with other data I have collected on other branches of this De Jongh family of Herwijnen and even in my own branch longevity and zealousness in a cause have been outstanding traits."