The Morins are one of the Belgian tribes. They were first mentioned by Julius Caesar, who had some difficulty with them. Their origin (and language) was probably Germanic. Caesar and Tacitus often cite them together with the Menapians, whose Germanic origin is not disputed. Boulogne-sur-Mer was their most important port, the port par excellence to access Great Britain for the Romans. Zosime (historian) specifies that Bononia (Boulogne) was Germanic at the end of the fourth century (Bononia germanorum).
Their territory, Morinie, had for civitas (Roman administrative capital) Tarvenna, Terwaan in Dutch which will become Thérouanne in French. La Morinie stretched from the mouth of the Scheldt in the north to the greater region around Calais.
Most of their territory was made up of polders, very clayey land unsuitable for habitation. The Morins lived there mainly on the edge, either to the west, on the coast, or to the east or south. Their name is derived from the word moer (marsh), a Proto-Indo-European word related to sea (French), mare (Latin), etc. A commune in the region is still called "Les Moëres" on the French side and De Moeren another commune on the Belgian side.
These moëres were from time to time flooded by the sea. mounds to build dwellings above. These mottes were called pol, compare with 'boule', hence polders. The Moëres were fertile, with good drainage.
The number of inhabitants at the time can be estimated at some 100,000 people. Their culture was despite their beautiful and much Celtic language.
Their army did not exceed 7,000 men and part of this army took part in the famous battle of Alesia.
The Morins survive in the modern Belgian province West Flanders. They kept their language very distinct, referred to as a dialect in the Dutch language group, but actually quite incomprehensible to the Dutch.