At https://martinsweatman.blogspot.com/2019/07/decoding-pictish-symbols.html … this post goes back to 2019 as I trawl through Sweatman’s web site. The Picts are thought to be a backward people because they painted their bodies, using woad or something similar. Actually, woad as a sort of war paint was used in Britain in general, even in the Anglo Saxon period. The colour blue had a symbolic meaning, we might suppose, as in India the god Krishna was also associated with the colour of blue. This idea of painted warriors comes down from comments from the Romans but nobody knows to what extent it was used. However, the Pictish symbols are usually found on megalithic style stone monoliths – or pillars in the words of Sweatman. Stone pillars are also a feature of the Welsh during the 5th and 6th centuries AD, but whether this was an internal tradition or inherited from Irish colonists of the period, is an unknown. Sweatman seems to be saying the Pictish symbols were a feature of Celtic pagan religion, presumably brought over by immigrants at some point in the past. Possibly in late second millennium BC, or early first millennium BC. On the other hand the symbols may have an even older origin, in the Neolithic – also immigrants from Europe. In that case there may even be a link to the druids. Who knows but the druids, according to tradition, had an interest in the sky. This is of course what Sweatman is suggesting – that Pictish symbols are astronomical. Unfortunately, the link has stopped working so there might be an update in progress. Sweatman intends to include this in his next book which is currently in the process of being written. If an update does appear I will update this post as I don’t want to say something that contradicts his new position.