In the Roman Catholic church this would also be considered a incestuous relationship. Any relationship between the 1st and 4th degree of consanguinitas or affinitas was considered to be incestuous.
Only the Roman Catholic Church forbid a marriage between a man and his stepmother. The law didn't forbid such a marriage. Overall there is no restriction on marriages between stepparents and their stepchildren or between stepbrothers and sisters. Nicolette
A big thank you to Petra, Boer 2 and Nicolette. I'm not surprised marriage to a stepmother was frowned upon by the churches, but am surprised it was legal.
On the Veluwe website I read "In the 'Echtordnung off ordinance op de houwelycken', which was issued on May 26, 1597 by the stadtholder, chancellor and councilors of Gelderland, in addition to enforcing the previously applicable provisions, marriage between cousins was also prohibited. This ordinance, reissued in 1627 and 1658, was replaced on October 9, 1660 by a new one, which, in addition to the prohibited marriage between cousins, lists other degrees of kinship between which marriage was prohibited, including the marriage of a man with the widow or his brother or with sister or his deceased wife, or a man with the widow. of his brother's or sister's descendants and of a man with the dv of his deceased wife's sister."
Nicolette, do you have a link to where the 1660 ordinance can be found?
The ordinance book, titled "Groot Gelders Placaet-Boeck" (Great Gueldrian Placard Book) as a collection of legislation texts of (collectively) the Duchy of Guelders (Hertogdom Gelre, Gelderland, https://en.wikipedia.org/wiki/Duchy_of_Guelders)and the County of Zutphen (Graafschap Zutphen, https://en.wikipedia.org/wiki/County_of_Zutphen ), seems to have appeared in 3 volumes, at least.
A register for multiple volumes together mentions this legal text, which was called [something like] 'Matrimony Regulation, or Ordinance upon the Marriages, with the annexes thereof, dated the 9th of October 1660' , as to be found in "2.D." (2de deel, tweede deel; 'second part', Volume 2). This regulation is probably what you're looking for.
The individual topics index/register, in that same Volume 2, refers to a page nr. 383 for said text:
...which is indeed where you will find that legal text, from pages 383-384:
Translating this obsolete Dutch into English, and finding the relevant section pertaining to stepmothers, will be a whole different question, I'm afraid... Lots of success!
Frank, this is wonderful. Clearly I have a lot of work ahead of me to understand more about marriage restrictions and the need or otherwise for dispensations.
All respondents have contributed greatly to my question which is now comprehensively resolved. Thank you so much for taking the time to help.
Thank you for this warning. Fortunately, so far all my 17th century research has been confined to Gelderland, though it probably won't stay that way for all branches. Fingers crossed :-)