The Charles Hartley bapt. 2 Sept. 1831 Preston, Lancashire - his father is named as John. There was a John Hartley born in Preston, Lancashire 8 April 1809. John's parents were Richard and Ellen. Whether or not this is the same 'John' I can't determine as yet.
My minor concern in finding 'Charles Hartley' is that we're actually looking for Charles Henry Hartley. I am quite new to this genealogy research, is it quite common for middle names not to be recorded on 'official' documents?
Yes, it is.
You can find say a birth for John Smith, right year, right location, right Mothers Maiden name. Census records him as John Smith then in another census John has become John Walker Smith, you know he is right because of parents and siblings.
It just happens, as does loosing a middle name, name changes, spelling, mis-transcription, disappearances, zero census records.
You will long for people with two or more forenames as your research progresses. The real joy is when Mother’s Maiden name or even one of the Grandparents surname is given as a middle name it does help a lot.
I have Thomas Drummer Thompson and his father Thomas Ewbank Thompson as xGGrandfathers so a good guide as to their parentage (floor cleaning jokes about the Ewbank middle name have had the life sucked out of them).
Do remember not all records are online and do not trust trees on Ancestry. Use them as a very rough guide and gather your own info.