instituted by Servius Tullius (increased to 35 in 241 B.C.E.), perhaps from tri- "three" + *bhu-, root of the verb
be. Others connect the word with the root of Welsh tref "town, inhabited place." In the Biblical sense, which was the original one in English, the Latin word translates Gk. phyle "race or tribe of men, body of men united by ties of blood and descent, a clan" (see
physic). Extension to any ethnic group or race of people is first recorded 1590s. Tribal "characterized by strong group loyalty" is recorded from 1951.