built earlier in the Iron Age, with construction ending around 100 AD, they remained in use into and beyond the Pictish period. Crannogs, which may originate in Neolithic Scotland, may have been rebuilt, and some were still in use in the time of the Picts. The most common sort of buildings would have been roundhouses and rectangular timbered halls. While many churches were built in wood, from the early 8th century, if not earlier, some were built in stone. The Picts were reported to have tattooed themselves during Roman times by writers such as the poet Claudian, and after the collapse of the Western Roman Empire, into the Middle Ages. However, evidence from the Picts themselves is limited. Naturalistic depictions of Pictish nobles, hunters and warriors, male and female, without obvious tattoos, are found on monumental stones. These stones include inscriptions in Latin and ogham script, not all of which have been deciphered. The well-known Pictish symbols found on standing stones and other artifacts have defied attempts at translation over the centuries. Pictish art can be classed as "Celtic" and later as Insular. Irish poets portrayed their Pictish counterparts as very much like themselves. Religion Early Pictish religion is presumed to have resembled Celtic polytheism in general, although only place names remain from the pre-Christian era. When the Pictish elite converted to Christianity is uncertain, but traditions place Saint Palladius in Pictland after he left Ireland, and link Abernethy with Saint Brigid of Kildare. Saint Patrick refers to "apostate Picts", while the poem Y Gododdin does not remark on the Picts as pagans. Bede wrote that Saint Ninian (confused by some with Saint Finnian of Moville, who died c. 589), had converted the southern Picts. Recent archaeological work at Portmahomack places the foundation of the monastery there, an area once assumed to be among the last converted, in the late 6th century. This is contemporary with Bridei mac Maelchon and Columba, but the process of establishing Christianity throughout Pictland will have extended over a much longer period. Pictland was not solely influenced by Iona and Ireland. It also had ties to churches in Northumbria, as seen in the reign of Nechtan mac Der Ilei. The reported expulsion of Ionan monks and clergy by Nechtan in 717 may have been related to the controversy over the dating of Easter, and the manner of tonsure, where Nechtan appears to have supported the