This may be more appropriate for anthropology, but I'm thinking specifically about references to the Germanic tribes of the migratory period and the numerous waves of Steppe tribes that were so important in Eurasian history. I'm vaguely aware that there's been a move towards viewing tribes such as the Franks, Huns, and Goths more as originating as confederations to which you could pledge allegiance and join more than an ethnic/genetic identity. Kind of like a giant gang, for lack of a better term. Can anyone provide some insight on what the current thinking is around this?
Tribe, a concept that has endeared itself to Western scholars and journalists for a century, is primarily a means to reduce for readers the complexity of the non-Western societies of Africa, Asia, Latin America and the American plains. It is no accident that the contemporary uses of the term tribe were developed during the 19th-century rise of evolutionary and racist theories to designate alien non-white peoples as inferior or less civilized and as having not yet evolved from a simpler, primal state. The uses and definitions of 'tribe' in the sociological and anthropological literature are varied and conflicting-some authors mean common language, others common culture, some ancestral lineages, and others common government or rulers.
This is a definition in a work about African tribes, but it summarizes well the issues surrounding this term while also suggesting some qualifiers that have been used in the past.