Tangwystl verch Dyfnwal

See Peter Bartrum, https://www.geni.com/documents/view?doc_id=6000000173392989909 (October 28, 2022; Anne Brannen, curator)

See Darrell Wolcott, "The Clan of Tudor Trevor," for work on untangling these lines -- http://www.ancientwalesstudies.org/id55.html (May 26, 2016, Anne Brannen, curator).

Please see Darrell Wolcott: Welsh Origins of the Peverel Family; http://www.ancientwalesstudies.org/id50.html. (Steven Ferry, April 15, 2020.)

Please see Darrell Wolcott: The Unofficial "History" of Elystan of Powys; http://www.ancientwalesstudies.org/id230.html. (Steven Ferry, August 12, 2020.)

Please see Darrell Wolcott: Refugees From Strathclyde Come to Gwynedd; http://www.ancientwalesstudies.org/id269.html. (Steven Ferry, June 8, 2021.)

Please see Darrell Wolcott: The Clan of Tudor Trevor; http://www.ancientwalesstudies.org/id55.html. (Steven Ferry, May 5, 2022.)