Human habitation of this elongated sand dune peninsula, 98 km long and 0.4-4 km wide, dates back to prehistoric times. Throughout this period it has been threatened by the natural forces of wind and waves. Its survival to the present day has been made possible only as a result of ceaseless human efforts to combat the erosion of the Spit, dramatically illustrated by continuing stabilisation and reforestation projects.
Formation of the Curonian Spit began some 5000 years ago. Despite the continual shifting of its sand dunes, Mesolithic people whose main source of food was from the sea settled there in the 4th millennium BCE, working bone and stone brought from the mainland. In the 1st millennium CE West Baltic tribes (Curonians and Prussians) established seasonal settlements there, to collect stores of fish, and perhaps also for ritual purposes.
The temperature increase in Europe during the 9th and 10th centuries resulted in a rise of sea level and the creation of the Brockist strait at the base of the Spit. This provided the basis for the establishment of the pagan trading centre of Kaup, which flourished between c 800 and 1016. This is unique in being the last unexcavated large proto-urban settlement of the Viking period.
The invasion of Prussia by the Teutonic Knights in the 13th century marked a major change in the historical development of the Spit. They were gradually driven out, but armed conflict continued in the region up to the 15th century. The Spit had great strategic importance, and in consequence the Knights built castles at Memel (1252), Noihauz (1283), and Rossitten (1372). They also settled German farmers around the castles, building roads and clearing woodland for agriculture.
The influence of the Knights ended with the peace treaty signed with Lithuania in 1422. Groups of Baltic peoples set up settlements on the Spit and the population increased. However, since their main activities were fishing and beekeeping, this had little impact on the natural environment of the Spit. The early 16th century witnessed the economic and political rise of Prussia, accompanied by intensive industrialization. Industries such as glassmaking, shipbuilding, and salt and metal production required large amounts of wood, charcoal, and potash, all of which could be obtained easily and cheaply on the Spit. Most of the woodland was felled to meet this demand. Loss of tree cover resulted in degradation of the vegetation and exposed the underlying sand to wind erosion.
In the 16th century a new process of dune formation began and settlements became buried in sand. By the early 19th century woodland only survived in a few places on the Spit, which took on the topography that has survived to the present day.
Large sums were made available by the Prussian State Land Management from the beginning of the 19th century to prevent further destabilization of the Spit. The works took the form of the construction of a protective bank of sand to prevent further ingress of dunes (a process that took most of the century) and the stabilization of dunes by means of brushwood hurdles, accompanied by reforestation. By the end of the 19th century nearly half of the Spit had been converted to woodland thanks to these works.
The battles of January 1945 saw considerable destruction of the woodland cover from fire, bombing, and the movement of heavy vehicles. Restoration work began after World War II and has continued with success, despite some serious incursions from the sea; nowadays woodland covers more than 71% of the surface area of the Spit.