Already in Bede's time the Wantsum was beginning to get silted up, mainly by the muddy deposits brought down by the Stour. It was then only three furlongs wide, and could be forded at two points, near Sarr and at Wade. The seaward mouth was also beginning to be encumbered with sand, and the first indication we get of this important impending change is the fact that we now hear less of Richborough, and more of Sandwich, the new port a little nearer the sea, whose very name of the Wick or haven on the Sand, in itself sufficiently tells the history of its origin. As the older port got progressively silted up, the newer one grew into ever greater importance, exactly as Norwich ousted Caister, or as Portsmouth has taken the place of Porchester. Nevertheless, the central channel still remained navigable for the vessels of that age--they can only have drawn a very few feet of water--and this made the Wantsum in time the great highway for the Danish pirates on their way to London, and exposed Thanet exceptionally to their relentless incursions. In fact, the Danes and Northmen were just what they loved to call themselves, vik-ings or wickings, men of the viks, wicks, bays, or estuaries. What they loved was a fiord, a strait, a peninsula, an island. Everywhere round the coast of Britain they seized and fortified the projecting headlands. But in the neighbourhood of the Thames, the high road to the great commercial port of London, the mementoes of their presence are particularly frequent. The whole nomenclature of the lower Thames navigation, as Canon Isaac Taylor has pointed out, is Scandinavian to this day. Deptford (the deep fiord), Greenwich (the green reach), and Woolwich (the hill reach) all bear good Norse names. So do the Foreness, the Whiteness, Shellness, Sheerness, Shoeburyness, Foulness, Wrabness, and Orfordness. Walton-on-the-Naze near Harwich in like manner still recalls the time when a Danish 'wall'--that is to say, a _vallum_, or earthwork--ran across the isthmus to defend the Scandinavian peninsula from its English enemies.