George Ryskamp, “La genealogía en el Patronazgo de 1616 de Francisco de Sosa, Obispo de Osma: El uso eficaz de genealogías antiguas,” III Congreso Iberoamericano de Ciencias Genealógica y Heráldica y XII Reunión Americana de Genealogía, Antigua, Guatemala, November 2005. English version: Effectively Utilizing Ancient Genealogies: The Genealogy in the 1616 Patronazgo of Francisco de Sosa, Bishop of Osma.”
This article proves the claim of Alonso de Sosa that his great great grandfather fought at the conquest of Granada. Ryskamp began with the genealogy of the descendants of a Estevan illan de Sosa, the founder of the chapel of San Martin, in an effort to ensure that money from his memorial trust went primarily to members of the his family.
The persons identified in the trust did not have much information other than their names and parentage, so Ryskamp combined the data with several already-published genealogies, and used name orders and ages typical of the time to guess general marriage dates, birth order, and general dates of birth, using any major markers in the document to adjust these dates for accuracy. He recognized that this was largely based off of assumptions, but by using the genealogical standards of today and the records of major events mentioned both within the document and elsewhere, he was able to construct the family tree.
Several times the information conflicted with family groups already established by genealogists, in which cases additional documents were used to verify which claim was correct. By using known patterns, already established work, and shaping the assumed births and marriages to major events, Ryskamp was able to successfully construct a family tree in an area with little other records.