I came across a set of early Trotter profiles that appeared to me to lack substance. Within a couple of generations one member becomes a PGM emigrant. However, according to a note from Anne B , this Trotter is not listed in the Great Migration directory.
In trying to find something about them and after searching through a quagmire of unsourced trees on Ancestry, I found that the source for the family at least (though not necessarily the migrant) probably derives from Burke.The 'fact' that Byers Green Hall has been the home of the Trotter family since the 15th century is attested to on wikipedia!
Then I found this debunking chapter which was apparently written by the historian J Horace Round. If true and Round is considered to be a good historian, It seems probable that there is a great deal of fiction in this pedigree.
However, I only have the chapter; to be an adequate source I really need to be able to find and cite the original book.
( addenda The wikipedia article cites
which comes from Burkes and has even 19th C Trotters of Byers Green Hall . Round looked at Kelly's directory for 1890 and found no Byers Green Hall and no Trotters. He couldn't use the census. I can and none of the 'illustrious' family from the pedigree that I looked for could be found in Byers Green. There was a family of Trotters, in Byers Green 1891 but they lived in Back Lane, John Trotter was miner and he had been born elsewhere in Durham)
(just tidying up question which looked messy after edits)