Almost all Scandinavian Iron Age bog deposits have been found in Denmark and southern Sweden, including Gotland.
The archaeology of a former lake at the Jutland site of Illerup Ådal is the best evidence [citation needed] for what are taken to be the sacrifice and destruction of the weapons and equipment captured from enemy soldiers (at Illerup, soldiers rather than tribesmen because a certain uniformity of equipment suggests professional organisation[1]).
The main Illerup deposition, besides weapons, includes gold, silver, spear shafts, shield boards, ropes, cords, leather, textiles tools, wooden vessels, spoons, beads, four horses and a cow.
A good number of deposit sites were in use for many centuries, with remains from several different sacrificial events, and they often includes many other types of offerings, such as animals, humans, boats, jewellery and food.
The weapon sacrifices from the Roman Iron Age times usually dates from the period 200–500 AD, but earlier ones from the pre-Roman Iron Age are also known, such as the Hjortspring boat offering form around 350 BC, where more than 50 shields, 11 single-edged swords and 169 spearheads accompanied the boat.
From grave finds of arrow heads, bows were significant war weapons in the Germanic area from about 200 AD.
[7] This change of weaponry is assumed to account for the Illerup shields having a layer of gut stretched over the surface.