The red lines show the overland trade routes, now known as amber routesA direct passage across the North Sea may also be suspected

"Inhumation in (tree-trunk) coffins was already starting to be practised in Schleswig-Holstein in the beginnings of its Bronze Age ... especially in Jutland. ... The same rite of boat- or coffin-burial appears simultaneously in Britain in the middle centuries of the second millenium, when the North Sea trade route was flourishing ... penetrating the Wessex culture ... but more prominent on the east coast, especially in Yorkshire, where the Irish route over the Pennines reached the sea. The ... Gristhorpe coffin-burial near Scarborough ... the great barrow of Loose Howe on the Cleveland Moors ... serve to show how the same rite took hold among the seafarers of both sides of the North Sea between about 1600 and 1400 B.C." From The Prehistoric Foundations of Europe; C.F.C.Hawkes, Methuen 1940; pp 365-66. 