Hello Mavis,

I can't find a marriage around 1869 in England for William Byford and Cath/Jane Cretney (which is not to say it isn't there), but there is one in the June quarter 1861 to Sarah Swift [District] Hull [Vol] 9d [Page] 285. You said that his wife's name on the passenger list was Sarah. Is it possible that he married very young (he is 18 in the 1861 census), the marriage didn't work out, and he and Jane Cretney (who was a visitor in his mother's house in 1871) left for a new life in NZ? If he had a free passage or was an assisted immigrant, which many were to NZ in the 1870s, he would have had to show proof of wife to obtain a free passage for her as well. This is just a guess, but could be the answer.
Another answer could be that the "Mar" for William in the 1871 census was wrong - George was entered as Ann's grandson, but as her son in 1861, and there were often errors in the returns.

However - there is a Sarah Byford in the 1871 census of Kingston Upon Hull, at 13 Little Queen Street, Head of family, Mar., 28, small Grocer's shop, b. Kingston Upon Hull, Sutton, with daughters Elizabeth Ann Byford 9 b. Sutton, and Gertrude Mary Byford 6, b. Sculcoates.
Judging by the age of the eldest daughter this looks like the above marriage, when Sarah also would have been only 18. That "Head of family" looks as though she and her husband were separated, although divorce was difficult to obtain at that time.

Surname First name(s) District Vol Page
Births Mar 1862:
BYFORD Elizabeth Ann Sculcoates 9d _17
Births Sep 1864:
BYFORD Gertrude Mary Sculcoates 9d 156

If it were possibly my family I'd buy that marriage cert. from the GRO, which you can do online, to find out the name and occupation given for William's father to confirm that it was his marriage. I don't think there's any doubt that it was your William Byford in the censuses, because he exactly matches your information.
In the 1871 census of Kingston Upon Hull, as previously mentioned, he was with his widowed mother Ann Byford, aged 62, b.Sussex, William aged 28, Oil Miller, b. Hull. (Also in household was Jane Cretney, 23, b.Isle of Man.)

In the 1861 census, Kingston Upon Hull, at 35 Church St., William Byford was aged 18, Oil miller, as son of James Byford, Head, Mar., 62, Labourer Grocer, b.Suffolk & wife Ann Byford 52 b.Sussex. Their other children were James Byford 20 Sailor Merchant b.London, Joseph Byford 16 stonemason, Paulina Byford 13, Sarah Byford 9, and George Byford 3, all born Hull.

In the 1851 census they are at 33 Church St., Kingston Upon Hull: James Byford, Hd, Mar, 43, Fruiterer & Greengrocer, b.Norfolk, Norwich; Ann Byford, Wife, Mar, 42, b. Sussex Barcombe; with children Jane Byford 12 b.Surry Vauxhall Lambeth, Paulina Byford 3 b.Yorkshire Hull, James Byford 11 b. Surry Vauxhall Lambeth, William Byford 10 b.Yorkshire Hull, Joseph Byford 3 b.Yorkshire Hull, and George Byford 1 b.Yorkshire Hull.

Those birthplaces look far more carefully recorded than in later censuses for the family, so are likely to be accurate. The son George could have died, and a later one given the same name, which was usual.

When answering, would you please click on Post Response, instead of starting a new thread, so that messages about the same subject stay together? Thanks.

Sue