In the period between 200 and 500 A.D. the Iron Age people sacrificed a large number of mostly weapons and army equipment in the lake of Illerup north of Skanderborg in East Jylland, following their many battles within the various Scandinavian tribes.
The lake of the river valley Illerup (Illerup Ådal) covered an area of ca. 10 hectares but would in time become overgrown, due to climate changes and landscape erosions.

Excavations started in the 1950’s have shown that over 15,000 objects have been offered by this lake. The excavations show that the finds were spread all about the bottom of what then was the vast lake, sacrificed over a series of three deposits. The first taking place around 200 A.D., during the early roman Iron Age, and the second two around 400 and 500 A.D respectively, that is during the Incursion Era.
Over 90% of the finds originate however from the first sacrifice, among them 150 Roman swords, 1000 spears- and lance-heads as well as personal items such as combs and tinderboxes, among others, were found.
They tell stories of how the area was strongly influenced by Roman culture.
Settlements have however not been found here but weapons, glass, pots and vessels were found in vast numbers. As well as a large number of roman silver coins (denare), gold rings, jewellery, tools and harnesses.
Furthermore there seem to have been two types of sacrifices in use, either by depositing offerings from the lake shore or by rafting them out to the middle of the lake and allowing them to sink.

Among the items found the advanced weapons of the time were also present, such as two-edged Roman swords and fine shields, many of them painted red with gold and silver mounts showing the status of prehistoric Scandinavian kings. Many items also had runic carvings which tell of intensive and direct contact with the higher levels of contemporary Roman culture.