The name Theydon Garnon comes from the family of Gernon. 'Theydon Garnon: Introduction', A History of the County of Essex: Volume 4: Ongar Hundred (1956), pp. 258-262. URL: http://www.british-history.ac.uk/report.aspx?compid=15703 Date accessed: 25 December 2012. Theydon Garnon was listed in the Domesday Book as "Taindena" / "Teidana", along with Theydon Bois and Theydon Mount.