From Wikipedia:
Curonian Kings (Middle Low German: Cursken konyngh; German: Kurische Könige; Latvian: kuršu ķoniņi) are a Latvian cultural group, originally lesser vassals and free farmers who lived in seven villages between Goldingen (Kuldīga) and Hasenpoth (Aizpute) in Courland.
It is unclear how Curonian Kings gained their status, however, a popular assumption is that their ancestors were Curonian nobility prior to conquest by Livonian Order. They were first mentioned in a document of 1320 and lived in the villages of Ķoniņciems, Pliķu ciems, Kalējciems, Ziemeļciems, Viesalgciems, Sausgaļciems, and Dragūnciems (now in Kuldīga municipality). All of them possessed independent farms (did not belong to any lord), but they were not allowed to own their own serfs. They had only one landlord komtur of Kuldīga and they were related to him only by military service in case of war. Curonians usually served as a light cavalry in the Livonian Order army.
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The Curonian Kings also were allowed to practice some aspects of paganism during the period of Livonian Confederation. Despite formal Christianisation after Livonian Crusade Curonian Kings owned a sacred forest where nobody was allowed to hunt or walk. It is possible that the first mention in written sources of those sacred forests occurs in the record left by the Flemish knight Guillebert de Lannoy in 1414. In 1413–1414, he travelled through Livonia to Novgorod, and has left a short description of a Curonian funeral in his travel notes:The aforementioned Curonians, although they have been made Christian by force, have a sect that, instead of burying their dead, burns them in a nearby grove or forest, dressed and adorned with the finest ornaments, constructing a pyre entirely from oak wood; and they consider that if the smoke rises straight up to the heavens, then the soul is saved, but if it is blown to the side, then the soul is lost.
— Guillebert de Lannoy (1414)Their Christmas traditions were described in a 16th century travel description by Königsberg apothecary Reinhold Lubenau:

-Curonian king woman from Turlava parish in Kuldīga region wearing traditional clothing (1895)
I find this quite interesting but I sadly did not manage to find more information on the subject. Perhaps someone here knows more?

