The All Saints' Flood of 1170 (Allerheiligenvloed) was a catastrophic flood in the

Netherlands , Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...

that took place in 1170. Large parts of the Northern Netherlands, and

Holland Holland is a geographical regionG. Geerts & H. Heestermans, 1981, ''Groot Woordenboek der Nederlandse Taal. Deel I'', Van Dale Lexicografie, Utrecht, p 1105 and former provinces of the Netherlands, province on the western coast of the Netherland ...

territories were overflowed. The flooding

North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...

created the islands of

Wieringen Wieringen () is located in the province of North Holland in the Netherlands. Now a part of the municipality of Hollands Kroon, it was a separate municipality before 2012. Its name first appeared in 8th and 9th century records. By 1200 it was an i ...

and

Texel Texel (; Texels dialect: ) is a municipality and an island with a population of 13,643 in North Holland, Netherlands. It is the largest and most populated island of the West Frisian Islands in the Wadden Sea. The island is situated north of Den ...

Lake Flevo The Zuiderzee or Zuider Zee (; old spelling ''Zuyderzee'' or ''Zuyder Zee''), historically called Lake Almere and Lake Flevo, was a shallow bay of the North Sea in the northwest of the Netherlands. It extended about 100 km (60 miles) inla ...

was once a fresh water lake, but a sea channel opened a connection from the North Sea into the lake through Creil Woods. Lake Flevo began to turn into the salt-water sea known as the

Zuiderzee The Zuiderzee or Zuider Zee (; old spelling ''Zuyderzee'' or ''Zuyder Zee''), historically called Lake Almere and Lake Flevo, was a shallow bay of the North Sea in the northwest of the Netherlands. It extended about 100 km (60 miles) inla ...

. By around 1248, the transformation of the lake into the Zuiderzee was complete. By around 1248, The Creiler Woods vanished under the waves. The sea area increased inside the Netherlands and large

peat Peat is an accumulation of partially Decomposition, decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, Moorland, moors, or muskegs. ''Sphagnum'' moss, also called peat moss, is one of the most ...

areas developed, which were easily washed away. The flood rendered the settlement of Rotta (the predecessor of

Rotterdam Rotterdam ( , ; ; ) is the second-largest List of cities in the Netherlands by province, city in the Netherlands after the national capital of Amsterdam. It is in the Provinces of the Netherlands, province of South Holland, part of the North S ...

) uninhabitable, and marked the beginning of

Amsterdam Amsterdam ( , ; ; ) is the capital of the Netherlands, capital and Municipalities of the Netherlands, largest city of the Kingdom of the Netherlands. It has a population of 933,680 in June 2024 within the city proper, 1,457,018 in the City Re ...

, where the area gained an open connection to the sea, and where a dam was built in the

Amstel The Amstel () is a river in the province of North Holland in the Netherlands. It flows from the Aarkanaal and Drecht in Nieuwveen northwards, passing Uithoorn, Amstelveen, and Ouderkerk aan de Amstel, to the IJ in Amsterdam, to which the rive ...

to protect the land from future floods.

References

Rome's Greatest Defeat, A Review - All Saints' Flood of 1170
. File retrieved March 11, 2007. *Buisman, Jan, ''Duizend jaar weer, wind en water in de Lage Landen (Deel 1: tot 1300)'', Floods in the Netherlands 12th-century natural disasters Medieval floods 12th century in the Netherlands Medieval weather events Texel Norderney 2nd-millennium floods {{flood-stub

See also

References