Svantevit's Oracle Horse at Arkona

Writing in Book 14 of his Gesta Danorum (c. 1200–1216), the Danish historian Saxo Grammaticus describes the temple of Svantevit at Arkona on Rügen in more physical and ritual detail than almost any other Slavic pagan site: a four-headed wooden idol holding a drinking horn and a sword, tended by a single priest forbidden even to breathe near the god's face without first exhaling outside the shrine.

Once a year, after the harvest, the priest filled Svantevit's horn with wine and, the following day, examined how much liquid remained: if the horn had emptied, it foretold a poor year to come; if it was still mostly full, abundance was expected. The priest then poured out the old wine at the idol's feet and refilled the horn for the coming year, a rite the gathered community watched as a forecast for the whole territory.

Saxo also describes a large white horse stabled at the temple, believed too holy for anyone but Svantevit himself to ride — priests claimed to find it sweated and muddied by morning, as though the god had ridden it fighting his enemies overnight. Before a military campaign, priests planted rows of spears in the ground, crossed in pairs, and led the horse over them: if it stepped over with its right foot first each time, the omen favored going to war; a stumble or a left-foot start called the campaign off. Saxo reports that the temple additionally received a tenth of all war-spoils taken by the Rani, kept in its treasury alongside tribute and ransom money, making Svantevit's cult also a center of very real material wealth and political power on Rügen.