The jurisdiction of a landgrave was a landgraviate and the wife of a landgrave was a landgravine.
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A landgrave by definition exercised sovereign rights.
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By marriage it passed to the landgrave of Thuringia, and after 1056 it formed for a while an independent country.
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For example, nothing in William's article indicates he even was a landgrave, yet there were landgraves of Hesse-Kassel named William.
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Landgrave Charles, who was responsible for this humanitarian act, also ordered the construction of the Oktagon and of the Orangerie.
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The theologians were not prepared to make a general ruling, and they reluctantly advised the landgrave that if he was determined, he should marry secretly and keep quiet about the matter.
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A count who had jurisdiction over a large territory in medieval Germany
Landgrave (Dutch landgraaf, German Landgraf; French landgrave; Latin comes magnus, comes patriae, comes provinciae, comes terrae, comes principalis, lantgravius) was a title only used in the Holy Roman Empire and later on by its former territories. ...
Anglicised rendering of Landgraf, a rare, specific nobiliary title ranking as count in certain feudal countships in the Holy Roman Empire, in present Germany; County nobleman in the British, privately held North American colony Carolina, ranking just below the proprietary (chartered equivalent ...