The Cymbrian flood (or Cimbrian flood) was a large-scale incursion of the sea in the region of the Jutland peninsula in the period 120 to 114 BC, resulting in a permanent alteration of the coastline with much land lost. This disaster killed many, and sent others living in the area south in search of new lands. It was one of a number of such conflagrations of nature in northwest Europe during the Roman period, the climate between 300 BC and about 100 AD producing frequent storms and the blowing of sand near the coast.
As a result of this flood, the tribes of the Cimbri, Teutons and Ambrones migrated south to the lands of the Romans, precipitating the Cimbrian War (113 to 101 BC). The contemporary Greek geographer Strabo, though sceptical, describes the flood and its consequences thus:
As for the Cimbri, some things that are told about them are incorrect and others are extremely improbable. For instance, one could not accept such a reason for their having become a wandering and piratical folk as this that while they were dwelling on a peninsula they were driven out of their habitations by a great flood-tide; for in fact they still hold the country which they held in earlier times; and they sent as a present to Augustus the most sacred kettle in their country, with a plea for his friendship and for an amnesty of their earlier offences, and when their petition was granted they set sail for home; and it is ridiculous to suppose that they departed from their homes because they were incensed on account of a phenomenon that is natural and eternal, occurring twice every day. And the assertion that an excessive flood-tide once occurred looks like a fabrication, for when the ocean is affected in this way it is subject to increases and diminutions, but these are regulated and periodical.
Researchers such as Jürgen Spanuth (1907–1998) have sought to push back the date of the Cymbrian flood by more than a millennium, severing its historical links with the wanderings of the Cimbri and Teutons and linking it instead with the Invasions of the Sea Peoples of the late 13th and early 12th centuries BC, driven from their northern homelands to attack the settled kingdoms of the Mediterranean.