he returned to ducal favor but continued to annoy Jean IV and Jean V with litigation until
his death on April 23, 1407, his seventy-first birthday.
The last male member of the family, Olivier IV had amassed a great fortune, and some
of Europe’s most important figures owed money to his estate. Through his older
daughter, the Rohan family acquired two-thirds of this wealth and became the greatest
noble family of Brittany. Olivier’s younger daughter, the countess of Penthièvre,
inherited her father’s propensity for feuding and litigation and brought ruin on her family
by inducing her sons to kidnap Jean V in 1420.
John Bell Henneman, Jr.
[See also: AURAY; BRITTANY; CONSTABLE OF FRANCE; CRAON;
HUNDRED YEARS’ WAR; JEAN IV; MARMOUSETS]
Bruel, François-Louis. “Inventaire de meubles et de titres trouvés au château de Josselin à la mort
du connétable de Clisson (1407).” Bibliothèque de l’École des Chartes 66 (1905): 193–245.
Buteau, Michèle. “La naissance de la fortune de Clisson.” Unpublished Mémoire de Maîtrise,
Université de Vincennes, 1970 (available at Vannes, Archives Départementales du Morbihan).
Gicquel, Yvonig. Olivier de Clisson, connétable de France ou chef du parti breton? Paris: Picollec,
1981.
Henneman, John Bell. “Reassessing the Career of Olivier de Clisson, Constable of France.” In Law,
Custom, and the Social Fabric in Medieval Europe: Essays in Honor of Bruce Lyon, ed.
Bernard Bachrach and David Nicholas. Kalamazoo: Medieval Institute, 1990, pp. 211–33.
Lefranc, Abel. Olivier de Clisson, connétable de France. Paris: Retaux, 1898.
CLOCKS AND TIMEKEEPING
. Devices to measure and indicate time are descended from astronomical instruments and,
like most complex devices, tend to have a history that is international in character. The
emergence of a purely mechanical timekeeper in the 14th century, the weightdriven
clock, marks a triumph of medieval ingenuity. The French contribution to this
development seems to have been in the construction of elegant timepieces and the
refinement of mechanisms originally invented elsewhere in Europe.
Monastic houses served as the context out of which mechanical clocks developed.
Water clocks with alarm mechanisms attached were used from the 11th century onward
to awaken the brothers for midnight services. The rules of Saint-Victor in Paris, for
example, made the registrar, a subsacristan, responsible for calibrating and adjusting the
water clock, while archaeological remains of SaintVillers abbey dated 1267–68 show a
detailed tablet on stone for this task. The only surviving manuscript illustration of a
medieval water clock is found in a French Bible moralisée of ca. 1285. In his addition to
the Roman de la Rose, Jean de Meun shows Pygmalion as possessing domestic versions
of these alarm “clocks.”
The earliest known examples of purely weight-driven clocks are English (Norwich,
1325; Saint Albans, ca. 1330) and Italian (Milan, 1333?; Padua, 1364), but the speed with
which these new devices spread was remarkable. Their acceptance was no doubt
enhanced by the fact that the weight-driven mechanism could be made quite large and
could drive all manner of ancillary machinery, especially puppet jackwork and bell-
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