influence within Brittany, especially in the records of the monastery of Redon in
southeastern Brittany and in the manuscripts and writings surviving from Landévennec
on the west coast. A distinctive Breton social organization based on the community of the
plebs (Breton plou), in which the machtiern was a powerful figure, is evident in
southeastern Brittany in the 9th century; affected by the growth of Redon’s lordship, it is
not traceable after the 10th century.
With the exception of Alain I (r. 888–907), Salomon’s successors found it increasingly
difficult to retain control over all of Brittany and to keep the Vikings out. From ca. 915,
the region was almost entirely in Viking hands and Breton leaders and churchmen were
in exile. Alain II (r. 936–52) returning from England in 936, took back Brittany,
including Nantes, Rennes, and the pays de Retz. Occasional raids from Normandy
continued until 1014, but Alain II began to restore the Breton church and may have been
the founder of the medieval bishoprics of Saint-Brieuc and Tréguier. His duchy had much
in common with other 10th-century territorial principalities, with a basis of Carolingian
administrative practices.
By the end of the 10th century, Alain II’s successors had lost the ducal title to the
counts of Rennes, whose weak authority was virtually nonexistent in western Brittany
and in Nantes. The emergence of powerful castellanies further altered the political
geography of Brittany. Throughout the later 10th and 11th centuries, the counts of
Rennes and of Nantes were caught up in the territorial ambitions of the counts of Blois
and of Angers and, increasingly, the dukes of Normandy. William I the Conqueror
already had Breton vassals by 1066, several of whom he endowed with English lands.
The honor of Richmond, granted to the sons of Eudo de Penthièvre, uncle of Conan II (r.
1040–66), remained in the hands of the Breton ducal family until 1399.
Norman lordship over Brittany was intensified by Henry I. Henry II integrated
Brittany fully into the Angevin empire: in 1166, the betrothal of Constance, infant
daughter of Henry’s vassal Duke Conan IV (r. 1155–66), to Henry’s young son Geoffroi
gave Henry the excuse to rule Brittany directly until Geoffroi came of age in 1181. The
firm rule of Henry, Geoffroi (r. 1181–86), and the duchess Constance (d. 1201) did much
to strengthen ducal power as revolts were crushed and a ducal administration established
similar to that in other provinces of the Angevin empire. The Assize of Count Geoffrey
(1185) changed rules of inheritance to reduce the fragmentation of fiefs and thereby to
safeguard military services. Henry II tried to revive the claim for a separate Breton
archbishopric, but in 1199 Innocent III definitively quashed Dol’s claims. The territorial
extent of Brittany—the Breton west plus the counties of Rennes and Nantes—has not
changed since unified as an Angevin province.
King John’s imprisonment and murder of Geoffroi’s posthumous son, Arthur (1186–
1203), gave Philip Augustus the opportunity to bring Brittany under Capetian influence.
In 1212, he married the Breton heiress Alix to his relative Pierre Mauclerc, who
performed liege homage for Brittany but after 1226 oscillated between allegiance to
England and France. With the help of French-trained administrators, Mauclerc (r. 1212–
37) and his son Jean I (r. 1237–86) took strenuous measures to build up ducal de-mesne,
revenues, and judicial and fiscal administration, to curtail seigneurial independence, and
to assert control over the church, particularly episcopal appointments and temporalities.
By the 14th century, ducal power was established and an effective household-based
administration with a network of local officials put in place.
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