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Early Middle Ages947 CE – 1491 CEPeak: 37,409 km² (1272 CE)

Duchy of Brittany: Map & History

The Duchy of Brittany was a medieval feudal state that existed between approximately 939 and 1547.

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947 CEDrag timeline:1272 CE1491 CE
947 CE
1100 CE
1200 CE
1300 CE
1400 CE
1491 CE
Capital: Nantes, Rennes, Vannes, and other citiesCapital at 47.22°N, 1.55°WPeak Extent: 37,409 km²Vector Attribution: Cliopatria (CC BY 4.0)Wikidata: Q71747 ↗
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Wikipedia: Duchy of Brittany
Duchy of Brittany historical cartography
Medieval feudal state in northwest France

The Duchy of Brittany was a medieval feudal state that existed between approximately 939 and 1547. Its territory covered the northwestern peninsula of France, bordered by the Bay of Biscay to the west, and the English Channel to the north. It was also less definitively bordered by the river Loire to the south, and Normandy, and other French provinces, to the east. The duchy was established after the expulsion of Viking armies from the region around 939. In the 10th and 11th centuries, it was politically unstable, with the dukes holding only limited power outside their own personal lands. The Duchy of Brittany had mixed relationships with the neighbouring Duchy of Normandy, sometimes allying itself with Normandy, and at other times, such as the Breton–Norman War, entering into open conflict.

Capital / Seat
Nantes, Rennes, Vannes, and other cities
Common Languages
Breton, Gallo, Latin, French, Poitevin
Imperial Currency
Various
State Governance
Feudal monarchy
Peak Territory
37,409 km²
Key Dynasts / Leaders
Allan II (first), Claude (last)
Preceded By
Kingdom of BrittanyBrittany, Viking Brittany
Succeeded By
France in the Middle AgesKingdom of France, (910-1593)
Content & infobox metadata adapted from Wikipedia (Duchy of Brittany)

Modern Countries Once Part of Duchy of Brittany

At its mapped extent, Duchy of Brittany covered territory in 1 present-day country. The period shown is when the mapped borders include that country, and the note says how much of it.

States and Provinces

Largest Present-Day Cities in Its Territory

Each opens on the live map inside Duchy of Brittany's borders of that time.

Derived by testing mapped cities against this polity's dated territorial polygons, so the list is indicative and follows the borders in the source dataset.

Duchy of Brittany in Depth

History

The Duchy of Brittany emerged after Alan Barbetorte's return to the region from England in 936. Barbetorte claimed the titles of the Count of Cornouaille and Nantes and, as Alan II, reigned as the new Brittonum dux. Using a network of small, defended towns and monastic sites, Alan pushed back the Viking advances. On 1 August 939, with the aid of Judicael Berengar, Count of Rennes, and Hugh I, Count of Maine, he defeated the Vikings in the Battle of Trans-la-Forêt, completing their expulsion from Brittany. Alan's duchy was smaller than the previous Kingdom of Brittany, as, despite gaining Magues and Tiffauges in the south, the dukes no longer ruled over the regions of Cotentin, Avranchin, and Mayenne. Alan paid homage to Louis IV of France for Brittany in 942.

Society, culture and governance

The north and western parts of the territory relied on a pastoral farming economy; the south-east enjoyed warmer weather and conducted mixed-arable and pastoral farming, based around small holdings. The region enjoyed a strong and diverse maritime economy including active ports of trade and fishing. Over the time of the Duchy, many currencies were present, and the Dukes of Brittany sometimes minted their own coins. Gold and silver were also used for trade.

In the 12th century, legends of Conan Meriadoc became popular in North-West Europe. By the 18th century these accounts had been described as mythical.

Legacy

There is no modern-day Duchy of Brittany. The Duchy of Brittany and the sovereign title and role of the Duke of Brittany no longer exist in the modern 5th Republic of France. The Breton Parlement no longer exists. Its seat was in Rennes. It was disbanded by Louis XIV but the Parlement voted to ignore the King's order of dissolution upon the claim it alone had the authority to dissolve this legislative and judicial body. Since 1956, there does exist the administrative Region of Brittany – which, however, includes only 80 percent of the former Duchy of Brittany. The remaining 20 percent of the former Duchy is the Loire-Atlantique department which now lies inside the Pays de la Loire region, whose capital, Nantes, was the historical capital of the Duchy of Brittany.

Background

The Duchy of Brittany that emerged in the early 10th century was influenced by several earlier polities. Prior to the expansion of the Roman Empire into the region, Gallic tribes had occupied the Armorican peninsula, dividing it into five regions that then formed the basis for the Roman administration of the area, and which survived into the period of the Duchy. These Gallic tribes – termed the Armorici in Latin – had close relationships with the Britonnes tribes in Roman Britain.

Sections adapted from Wikipedia: Duchy of Brittany (CC BY-SA 4.0).

Duchy of Brittany: Key Facts

Key facts about Duchy of Brittany
CapitalsNantes, Rennes
Form of governmentfeudal monarchy
Founded939 CE
Dissolved1547

Facts from Wikidata Q71747 (CC0).

Duchy of Brittany Map Over Time

Dated world maps on which Duchy of Brittany appears, with the other states of the time.

Duchy of Brittany Timeline

Key historical inflections from foundation to peak territorial expansion

1 Epochs
Territorial Apex1272 CE

Expansion to peak recorded area of 37,409 km² in 1272 CE.

Duchy of Brittany: Frequently Asked Questions

When did Duchy of Brittany exist?

Duchy of Brittany is dated to 947 CE – 1491 CE, in the Early Middle Ages era.

What was the capital of Duchy of Brittany?

The capital of Duchy of Brittany was Nantes, Rennes, Vannes, and other cities.

How large was Duchy of Brittany at its peak?

At its peak in 1272 AD Duchy of Brittany covered about 37,409 km².

How did the map of Duchy of Brittany change over time?

Duchy of Brittany appears on 4 dated world maps in the atlas, from 1000 CE to 1400 CE. Each shows its borders in that year next to the other states of the time.