Geoffrey of Monmouth
2 of the 7 encyclopedias on this shelf carry an entry for Geoffrey of Monmouth. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
a famous English chronicler; born probably in Monmouth about 1100. He was the author of a famous chronicle or history of the first British kings, often quoted by men of letters and remarkable for its curious legends. Geoffrey was successively archdeacon of Monmouth and bishop of St. Asaph. He died in Llandaff in 1152 or 1154. GEOFFROY ST. HILAIRE, ETIENNE (zhō-frwä' san-të-lar'), a French naturalist; born in Etampes, France, April 15, 1772. He was educated at the colleges of Navarre and Lemoine. At the age of 21 he obtained the chair of zoology in the Parisian Jardin des Plantes. As a member of the Egyptian expedition in 1798 he founded the Institute of Cairo, and returned about the end of 1801 with a rich collection of zoological specimens. In 1807 he was made a member of the Institute, and in 1809 Professor of Zoology at the Faculty of Science. He devoted himself especially to the philosophy of natural history. Among his principal works are: "The Principle of Unity in Organic Composition"; "Philosophy of Anatomy"; "Natural History of the Mammifers"; "Ideas of Natural Philosophy" (1838). He died in Paris, June 19, 1844.
Aiton's Encyclopedia (1910)
an English chronicler. He was born probably at Monmouth about 1100 and died about 1154. He entered the society of Benedictine monks and was raised later to the bishopric of St. Asaph. He wrote several works, the most important of which, Historia Regum Britanniae, is a history of the kings of Britain. The work is chiefly a translation of early manuscripts, and is legendary rather than historical. It gives what claims to be a genealogy of British kings from the time of Brutus, the Trojan, down to 688. Geoffrey's work is of no historical value, but it has preserved the traditions of King Arthur and his knights, the story of Sabrina, the story of King Lear , and many other legends.