The Picts were the aboriginal inhabitants of what is now known as Scotland. The name "Pictii" refers to several tribes that were extant in the area in classical times; the Caledonii, the Scotti, the Mæatæ, the Britanni, and so forth. The name of "Pict" does not occur in writing until the end of the third century, however.
By the seventh century, we find a Pictish Kingdom, defeating the Angles at the Battle of Dunnichen in 685, but from that point on their history declines into an unknown darkness.
The primary point of note in modern eyes concerning the Picts is their custom of painting themselves blue, in a similar fashion to the rest of the native Britannic tribes. This custom will be shown to be a significant point in our search for the Pict's descendants.
Scotland was invaded by the "Scotii" from Ireland, and by the Danes in the north, both of whom took over the Highlands, while the Norman invasion of 1066 led to the Lowlands being over run by Normans and perhaps a few displaced Anglo-Saxons to add to the Angles already there from the invasions of the seventh century.
So what became of the Picts? Where are the people that Rome feared so much? Where are the "blue men" of Caledonia?
There are several theories. One of the most probable is that the Picts wound up being absorbed into the rest of the population of the Highlands, and there is archaeological evidence in the Isles that this in fact did occur to some extent, BUT......
In the absence of historical records, and with the paucity of archaeological evidence, we must look to that other source of historical information: Folklore.
It is quite common for the aboriginal inhabitants of a land to devolve to the status of "little people," of elves and fairies. (This corresponds to the old saw about the gods of the old religion becoming the devils of the new.)
In the folklore of the British Isles we find this thread. We find elves, fairies, kobolds, dwarves and the like, many times described as "little people." In addition, they are described as wearing caps, much of the time, and have a knowledge of magic. They tend to be described as "good folk," showing that they are probably considered to be "nice" and kindly in nature, albeit mischevious at times.
In Scotland, we see the "Cruithneach," who are also known as "Pechs" in the vernacular of southern Scotland....from "Pict" to "Pech" is an obvious lingual change...and they fit the above description.
Therefore we need to find a race of people who are: