He is my 25th great grandfather.

Thanks, Eric. That is great stuff and of considerable interest to me.

My sources for my line to Llywelyn are (primarily):

Frederick Lewis Weis and Walter Lee Sheppard, Ancestral Roots of Certain American Colonists Who Came to America Before 1700, (Baltimore: Genealogical Publishing Co., 2004).

Boyer, Carl, Medieval Welsh Ancestors of Certain Americans, (Santa Clarita, CA: Carl Boyer, 3rd, 2004).

Roberts, Gary Boyd, Royal Descents of 600 Immigrants to the American Colonies or the United States, (Baltimore: Genealogical Pubishing Company, 2004).

Marston Watson, Royal Families: Americans of Royal and Noble Ancestry, Vol. Two: Reverend Francis Marbury, (Baltimore: Genealogical Publishing Co., Inc. 2004).

Robert Charles Anderson, The Great Migration: Immigrants to New England 1634-1635, Vol III, G-H, Boston: New England Historic Genealogical Society, 2003.

Colket, Meredith B., The English ancestry of Anne Marbury Hutchinson and Katherine Marbury Scott..., Philadelphia: Magee Press, 1936.

After those, I rely on census data, several secondary sources (family books), our family Bible, and vital records.