Interviewer asked if I had a partner/ was married

I was at an interview yesterday for an accountant role. One question that I was asked was if I was married or had a partner. For context I am a 31F and not currently married but intend to be in the near future and want a family. Reading between the lines I can only suspect they were trying to decipher whether I was going to be having a family within the next few years, which presumably will sway their decision of whether they will give me a job offer. I’ve never been asked such a question in a job interview before and it really threw me and made me feel uncomfortable. Am I wrong to think that this question was inappropriate to ask a female candidate or is this normal? EDIT: many thanks for such a vast response to my post and comments - greatly appreciated. Just to add, I am based in Scotland this particular role was for a management accountant role within a landed estate.