These are the family trees of the surnames Nelson and Roman.

The Nelson name starts in Kent going back to London, England. It ends up in Glasgow, Lanarkshire, Scotland, Alexander Nelson's grandparents, Alexander Neilson and Grace Russell are where the surname changed. Grace Russell's parents were born in Ireland. The Neilsons (Sons of Neil) are supposed to be descended from the Clan of McNeil. McNeils are likely Viking descendants rather than from the Nine Kings of Ireland. A direct link has not yet been found. The oldest ancestor is William Neilson a coal miner. This branch of the family follows Scottish naming conventions, where children are named after their grandparents.

The main maternal branches are Blair, Cliff and Tollafield. One Nelson has married into the Irish Dohertys of Donegal and now lives there. I have recently been in contact with Agnes Blair's sister Margaret's descendant Margaret and have a lot of her branch to add. 

The Cliffs and the Tollafields seem to be the most travelled, with relatives originating in Burton-on-Trent, Staffordshire and Suffolk, moving to Kent and Gloucestershire. Some travelled as far as Canada and Australia. Lillian Tollafield's brothers all emigrated to Canada and one went on to Detroit, Michigan, USA. I was given a large Gedcom file from Pauline Isaksen. It contains a great many Tollafields, which I am still adding. She is  Pauline L. Tollafield; Lillian V. Tollafield's father's second cousin's granddaughter. She married a Norwegian and now lives there. She is also a published author. So we have Norwegian cousins. 

Following back the Tollafield branch, we have the surnames Keep, Tuck, Cooper and Small.
Following back the Cliff branch, we have the surnames Sharratt, Clifford, Ward, Pitt, Digby and Barham

The Romans lived in London and most likely originated from Ireland and were quite poor. The Dixons were in comparison well off. Mostly both branches were from the Camberwell, Walworth areas of East End of London. An area was known for huge settlements from Ireland and Poland with large Romani and Jewish communities. Romans are rumoured to be of Romani descent, but no link has been found. Kent Hopping was a regular feature for these families. They gradually moved south-east to Essex, Surrey and Kent.

The main maternal branches are Dixon, Eglese and Oastler. The Egleses are mostly from Peckham, London. The name is likely of french origin, Eglese meaning church or a variant of Eagles.

The Dixons are proving very tricky, as they had not only variations of names but the names of their streets were also changed. Dixon is the English variant of Dickson, which may be a derivative of Dickinson. I was given paper copies of extensive research on the Oastler branch. This branch is huge as Caroline Oastler had up to 20 children, I haven't found them all yet. Oastler has various spellings going back. Ostler, Osler, Ossler, Hostler.