OK, James Haines' marrage certificate arrived today, confirming that he married Matilda Harrison at Narborough on Feb 24th, 1858, and that her father's name was John. James' father's name was also John and the occupations of both fathers is given as "Felt knitter". Another useful detail is that one of the witnesses was Joseph Haines, who was probably a brother of James.

First point to note is that in the 1861 census James and Matilda have a 3 year old son, George, who seems to have died later that year. The PRO Index lists a George Haines born Blaby in the 2nd quarter of 1858 which means that Matilda must have been well and truly pregnant at the wedding!

The other point is that James' age is given as 38, suggesting that he was born in 1819, while the 1861 census suggests 1815 (age 46) and the 1871 suggests 1813 (age 58). Matilda's age on the marriage certificate is 21, which was probably stretching it, since in the 1861 census her age is given as 23 and she was 13 in 1851.

I can't find an entry in the birth index for Matilda's birth, and of course the really annoying thing is that William's birth certificate states that his mother's name was Ann. I suppose I'll have to try Narborough Parish Registers to be certain.

Found the Harrison family in the 1851 census and a couple of doors away lives a William Haines, born Narborough, like James and whose year of birth would be about 1818. It certainly seems plausible that James came to visit cousin (or brother?) William and struck up a relationship with the neighbour's young daughter which resulted in the creation of the future ill-fated George Haines. Presumably they had little choice but to get married.

There is a James Haines in the 1851 census, but his age is given as 28. Next door to him is a John Haines age 50, who is not old enough to be the father of anyone born in 1813, but could have fathered someone born in 1820.

I did find a Joseph Haines in the 1861 census, born Narborough about 1827, who surely must be the witness, so I'm inclined to believe that James was born in about 1820 and that for some reason his idea of his age became more and more exaggerated as his life drew on.

If only I could be certain of this ...