Marris is one of few present-day English families that can be traced back, through the male line, to an ancestor who fought with William the Conqueror at the Battle of Hastings in 1066. The Marris pedigree was accepted by Ulster Office, Dublin Castle in 1938, and was registered with the College of Arms in London shortly afterwards. It was later published in the 1952 edition of "Burke's Landed Gentry". This book sets out how the original research began in the early 1900s and the way in which it was undertaken. It describes twenty-nine generations of the family, starting with Osbert, a Domesday tenant, and finishing with Harold Colquhoun Marris OBE who died in 1966. References to original sources are provided. Old family photographs are included, as are short biographies of some of the family members. Harold C. Marris's dealings with Deputy Ulster King of Arms in the 1930s and 1940s are described, as are his dealings with L. G. Pine, the then editor of "Burke's Landed Gentry".