There are many sources which can be used to document the facts regarding a particular family tree. This becomes more important as you travel back in time to search for those ancestors. The above figure shows the front page of one major source for Welsh family tree. "Dwnn", as it is most commonly referenced, is a primary source (document) for those doing Welsh genealogy. His "Visitations of Wales" dating between 1586 and 1613, records the many, many families who claimed a lineage under the "Deputy Herald At Arms". Transcribed from the original manuscripts, this source records the families in Wales during this period of history. These records were then edited and numerous explanatory notes (including errors and corrections) were added by Samuel Meyrick and published in 1846. This becomes the standard reference for those doing Welsh genealogy.
A second source is shown to the right. It is most often referred to as "Burke's Armory". It is titled as an record of "Armorial Bearings" from the earliest time to the present. Of course, the present was 1884. This document contains families from England, Scotland, Ireland, and Wales who record "Armorial Bearings". Many folks in the academic world seem to disregard Burke as full of errors and mistakes. These errors are certainly not clearly identified, but for many, this is a valuable source for the genealogist.
Finding a reliable source for genealogical research is necessary as one goes out the branches of any family tree. These two I have necessary for Welsh genealogy. More to come.