Thank you for your reply! I simply googled in my search for Thomas More pedigree-suggestions, to see if there were some mention of Ullathorne in any of them. Fortunately I landed on this thread and did not have to look further :-)
Yes, you are right, the people you mention are relatives. I visited Oldham in October to try to find more information about them than I have already found out by census information and other internet sources. The birth of Jane Ullathorne to William Ullathorne and Sarah (Allinson) is the right one. They were probably not catholic. However, her husband Frederick Warbrick was a methodist and the parish registers of his children seem to be lost (Hope Chapel in Oldham).
Thomas Ullathorne married Abigail Cowling in Leeds 2 mar 1789, and they baptized at least three children there: Hanna (1790), John (1791) and James (1798). John is my ancestor. He married Hannah Taylor in Leeds in 1809, and had among others, William Ullathorne in Selby in 1820. He married Sarah Allinson in 1841. Jane Ullathorne was Frederick Warbrick's second wife.
Thomas Ullathorne (1766-1819) and William Ullathorne (1757-1816) had a brother Francis (1760-1837) who, with his sons and the Longstaffs, founded Ullathorne & Co i 1798 - a flax and shoe thread mill with head office in Holborn, London, a mill at Bernard Castle in Durham and at Startforth, and with branches in Australia and Paris.
You may send me an e-mail at "kristinn dot hegna at nova dot no" if you would like me to send you more information. (I'm afraid I would have trouble finding you adress from here)