From PathfinderWiki

Thane is a title denoting a person as a retainer to a regent, sometimes equivalent in rank to an earl.[1] The title of thane was common in Irrisen among the Djurstor Confederacy prior to Baba Yaga's conquest, and many thanes of the Confederacy are interred in the Thanegraves of western Wintercrux.[2] It is also used in the Lands of the Linnorm Kings, where the Thanelands are one of its seven kingdoms[3] and Thanesrest Mausoleum once served as a mausoleum to kings of Broken Bay.[4]