Hetmanate:
the authority, rule, or domain of a hetman. [Dictionary.com]
The last time I ran across hetman was in a Jack Vance novel titled The Killing Machine. I’ve never bothered to look it up before.
the title assumed by the chief of Ukrainian Cossacks of the Dnieper River region, with headquarters at Zaporozhe.
Noted in “Ukraine’s Lost Capital,” Daniel Weiss, Archaeology (September / October 2023):
In 1569, Poland and the Grand Duchy of Lithuania, which included Ukraine, united to form the Polish-Lithuanian Commonwealth. Chafing at this new entity’s efforts to control them, many Ukrainians took refuge on the frontiers to the south and east known as the Wild Fields. There, they were able to pursue a life of independence and adventure and came to be called Cossacks, derived from a Turkic term meaning “free men.” The Cossacks established successful farms, which they had to defend against persistent threats from the Ottoman Turks and their allies the Crimean Tatars to the south. Over time, the Cossacks became the political elite of Ukraine and, along with members of the Orthodox clergy, started to demand the right to rule themselves. After a series of failed uprisings, in 1648 the Cossacks achieved their goal. Led by their hetman, Bohdan Khmelnytsky, they threw off the yoke of Polish rule, attaining a measure of independence and establishing a state known as a hetmanate.
