Sentence:  The supreme political unit of the tribe was the assembly of its free male warriors. This assembly, called the "<WSD>Thing</WSD>", served as the court of highest instance for dealing with individuals who had broken fundamental elements of the tribal pact, an occasion to meet and to reinforce ties among members, and, often, an assembly which preceded a military campaign. 
Meaning of the word marked with <WSD> tags:  A public assembly or judicial council in a Germanic country.