Research Notes:
A biosketch [1] reports:
Thomas Holbrook, married Constans Thayer at Thornbury, Gloucestershire, February 19, 1560. Thornbury is only a few miles north of Glastonbury, which was probably the home of Thomas Holbrook. William Holbrook of Glastonbury, the father of our American progenitor, named his first male child Thomas. There are many other circumstances that make it probable that Thomas and Constans (Thayer) Holbrook were the parents of, William Holbrook
[1] A. Roberts Lord, Holbrook and Allied Families (New York: Thesis publishing Co, 1942), 5-6, [HathiTrust].