Begun by George E. Cokayne, the Clarenceaux King-of-Arms, this set is to the British peerage what the Oxford English Dictionary is to the English language -- absolutely the best thing of its kind! Citations to primary sources frequently fill 3/4 of the page and anecdotal text notes put some meat on the bones. Far superior to the 19th century Burke's Peerage publications. Don't attempt serious British peerage research without it! The numerous appendices at the ends of the volumes also are highly recommended as instructive essays.