Hi Annie,
I saw your query re: Rudkin/Keightley and joined RootsChat, just so I can let others know what I discovered several years ago, and which, I believe, explains the confusion as has been discussed at length on the internet over several years. I am a descendant of Theresa Harris, nee Rudkin, daughter of Matthew Rudkin and Sarah, nee Orange. Matthew was born at Blaby and his father was Roderick.
Matthew descends from a line of master bricklayers and builders, as is commonly known. Well, one day in the Leicester Records Office I stumbled on a book of "Freemen of the City of Leicester" and it gave a list of all the masters and their apprentices and the dates at which their sons were subsequently made freemen. I am in a library at the moment and do not have my notes to hand, but from memory, Matthew's direct paternal grandfather, or great grandfather was, I think James Keightley, but he was apprenticed to a (Thomas?) Rudkin who was a mason at Newtown Linford, and when James had qualified he obviously agreed to take on the surname of his master. This is what must have happened as the book which lists and traces back all the subsequent sons etc keeps saying "Rudkin, alias Keightley" or "formerly Keightley" or "now Keightley."
Because there are references on the internet to researchers having found Rudkins marrying Keightleys etc, I actually believe that the two families were related already, maybe Thomas Rudkin had no male heir, but agreed to take on his nephew?? as long as he would assume the surname Rudkin. I do not think it is a case of illegitimacy and the keeping of an unmarried mother's name. So the Rudkins are, I believe, in fact all Keightleys!! Because of their line of business they simply kept the original surname going by christening lots of their sons with the middle name Keightley, although they now were legally known by the surname Rudkin.
I hope this is useful. I can supply you with the exact facts/words if you wish, but the book is easily located at the records office and does, I believe, solve the big Keightley/Rudkin question.
Nick