The term caput gentis being used by Tacitus may not only denote a capital in the sense of a single large fortified settlement, but it could also refer to a central place of worship. In the latter case it is conceivable that Mattium comprised a larger area consisting of various ritual sites and settlements connected to them rather than being a single central settlement.Karl Ernst Demandt: Geschichte des Landes Hessen. Stauda Verlag Kassel, 1981, p. 23, 31, 63, 84, 95, 115. (German)
