Wales Genealogy - FamilySearchWiki
: "The International Genealogical Index for Wales can be difficult to use unless you understand a few points. The Welsh names in the International Genealogical Index have come from two main sources: a systematic extraction of the christenings, births, and marriages in church and chapel records and entries submitted by individual researchers. The Parish and Vital Records List is a list of the records and time periods that were systematically extracted. This list is available in print or microfiche formats at the Family History Library and in the Family History Centers.
Many Welsh people did not have surnames in much of the period covered by the International Genealogical Index. They used patronymics. For an explanation of patronymics (see the 'Names, Personal' section of this outline). Other families had established surnames. In 1813, the Established Church in Wales started using a standard, printed form for their parish registers, which included a column for surname. This made it relatively easy to determine if the family was using patronymics. Before that date, there wasn’t a surname column, so there was no way to determine if 'William the son of John Thomas' would grow up to be 'William John,' 'William Jones,' 'William Thomas,' or by another name.
Welsh naming customs created a need to standardize the extraction of names for the International Genealogical Index. . . . .
Due to the intricacies of early Welsh land tenure and the unchallenged jurisdiction of tribal laws, a tribe member, upon reaching 14 years of age, had to establish his freeborn status with the tribe. Knowing his genealogy for at least nine generations was required for him to get his inheritance. Many Welsh pedigree collections have been produced from this tradition.
The Family History Library has some collections of Welsh genealogical material, including published and unpublished collections of family histories and lineages as well as the research files of prominent genealogists. . . . .
Since most persons with the same surname are not related, you may have to do some research to connect your family to a family listed in one of these sources.
Ancestry.com - If You Are Researching Welsh Ancestors...: "The second interesting feature of Welsh research is Welsh descent may be either unknown or difficult to prove. Emigrants from Wales have been “lost” in their new homelands, lumped together with the English by immigration officials in North America and elsewhere. Records indicate that of the British immigrants arriving in America in the 1860s, 2% or about 4,000 were Welsh, yet the census of 1870 reveals that nearly 30,000 stated they were born in Wales.
Similar disparities occur in numbers for the 1700s. In other words, family tradition can be at odds with official documents and some records, such as census returns, can be different from immigration records."
FamilySearch.org - Research Helps:replacing the older research guides