The famous picture stones of Gotland are like Viking rune stones from Scandinavia, but they have pictures and fewer runes. The themes and images depicted on them developed over the Iron Age and into the Viking Age. Originally they seem to have pertained to some kind of Indo-European solar cult involving horses, but later stones have more familiar figures from Norse mythology.
Early stones could have served as grave monuments which may explain the solar iconography focusing on the eternal solar cycles. The