Grimm's Ditch

Grim's Ditch, Grim's Dyke (also Grimsdyke or Grimes Dike in derivative names) or Grim's Bank is a name shared by a number of prehistoric bank and ditch earthworks. Enigmatic in both their naming and original function, examples are found across the chalk uplands of southern England.

The purpose of these earthworks remains a mystery, but as they are too small for military use they may have served to demarcate territory. Archaeologists agree that Iron Age peoples built the earthworks around 300 BC. Today, Grim's Ditch forms a section of The Ridgeway National Trail, a long distance path and one of the 15 National Trails in England and Wales.

The name "Grim's Ditch" is Old English in origin. The Anglo-Saxon word dīc was pronounced "deek" in northern England and "deetch" in the south. The method of building this type of earthwork involved digging a trench and forming the upcast soil into a bank alongside it. This practice has resulted in the name dīc being given to either the excavation or the bank, and this evolved into two words, ditch and dyke in modern British English.

The origin of the name Grim is shrouded in mystery, but there are several theories as to its origin. Many ancient earthworks of this type exist across England and Wales, pre-dating the Anglo Saxon settlement of Britain by some 800 years. It was common for the Anglo Saxons to name features of unexplained or mysterious origin Grim. Most scholars believe that the name derives from the Old Norse word Grimr, an Anglo-Saxon alias for the Norse God of War and Magic, Wōden (called Odin by the Norse) and meaning "the masked one". The name of Wōden is thought by some historians to be evident in Wansdyke, an ancient earthwork of uncertain origin which runs from Wiltshire to Somerset. The historian W. H. Stevenson draws a link between Grim, the Saxon alias for Wōden, and the name of Grim's Dyke:

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