My take on William and Margaret Pugh living in London in 1881 lead to the above tree. Aled Pugh suggested that the father of this William and Ann Pugh (a Rees Pugh, born Dolgellau 1820) might be the brother of "our" Evan Pugh (born Llanfachreth or possibly Dolgellau in 1826). I don't think he can be a brother, as the census information shows him to be the son of Rees & Catherine Pugh of Dolgellau - both the census information, Dolgellau baptism records and his marriage certificate show these to be his parents. The marriage appears to be Rees Pugh marrying Catherine Williams at Brithdir Independant Chapel, Brithdir, Merionethshire on 4 May 1799. "Our" Evan Pugh has a father "Richard" not "Rees" on his marriage certificate. Rees Pugh b1820 was the father of the William and Margaret whose house in Hammersmith Mary Ann Pugh lived in 1881 while having her illegitimate child. The arguement requires a bit of concentration but is as follows
Aled posed the question as we know that a daughter of "our" Evan Pugh (b1826), one Mary Ann Pugh (a proven daughter of Evan b1826) had an illegitimate child William born in London. The 1881 census shows her staying in Hammersmith, London with William Pugh (dairyman aged 25, b Tynycornel, Dolgellau) and his sister Margaret (age 19, b Tynycornel, Dolgellau)
Mary Ann is down as a visitor. Mary Ann gave birth to a son in London a few weeks later, whom she named William. Three years later Mary Ann had a second illegitimate son John Evans Pugh. Tragically, he died in 1907 aged 23 due to a coalmine accident in Treorchy, South Wales. He was brought home to be buried in his grandfather Evan Pugh’s grave in Talyllyn churchyard. The 1901 census records Sulfanws and William as also being coalminers, staying in a boarding house in Cwmpark, Rhondda. It is probable that by 1907 John Evans Pugh had joined them to work in the coal industry of South Wales. Mary Ann Pugh did eventually marry and had a daughter Susanah Jane.
From censuses we can see that Rees Pugh was born circa 1820, and married Catherine and that they had a number of children. We are then going to work back to get his parents.
And following their marriage, Rees and Margaret are living in these locations
From census 1841, this Rees Pugh would seem to be the son of Rhys & Catherine Pugh, farmer of Tynwydd, Dolgellau. The 1841 census does not give relationships, but Catherine Pugh age 9 would appear to be a grand-daughter, given the age of the senior Catherine Pugh (age 60 Rermember rounding, in fact one sees from 1851 census that she was 64 in 1841)
Note that their children Robert and Rees in the 1841 census, tie in with the baptisms of children of Rees and Catherine Pugh at Dolgellau church.
Both Rees senior and Rees (b1820) can be followed through the censuses.
Abstracts from censuses
1851 census Rees (senior) has died
Now while researching Ann Pugh (whom I believe to be a daughter of Richard Pugh (b1788) had a Elizabeth Pugh as a visitor in the 1881 census. I linked this Elizabeth to be a daughter of Rees and Catherine. Oddly she seems to be recorded as "Ann" in the 1861 census below.
1861 census (whole page here)
1871 census for Tynycornel shows:-
1881 census for Tynycornel shows
And the ones living in Hammersmith
1891 census shows Margaret Pugh, a widow living alone
Evan Pugh 1826