WASH, THE, a shallow bay of the North Sea, on the Lincolnshire and Norfolk coast of England. It is roughly square in shape, penetrating the land for 22m., and being 20 m. wide at the head and 12 at the mouth. Through the sandbanks which form its bed there are two main channels into deep water; one, Boston Deeps, is kept open by the waters of the Witham and Welland; the other, Lynn Deeps, gives passage to those of the Nene and the Great Ouse. The Wash is the remnant of a much larger bay, which covered a large part of the Fens which now border it; it is gradually filling with the deposits of the rivers, and from time to time small portions are reclaimed (see Fens). The flat bordering lands are protected by sea-walls. The formerly dangerous passage of the marsh-lands, which were liable to irruptions of the tide, is illustrated by the accident to King John in 1216 shortly before his death. Passing over the Cross Keys Wash, near Sutton Bridge, his baggage and treasure wagons were engulfed and he himself barely escaped with life.