Each of the Five Tribes retained its local self-government. The supreme government of the confederacy was vested in a General Council of fifty sachems, "equal in rank and authority." The fifty sachemships were created in perpetuity in certain clans of the several tribes; whenever a vacancy occurred, it was filled by the clan electing one of its own members; a sachem once thus elected could be deposed by the clan-council for good cause; "but the right to invest these sachems with office was reserved to the General Council." These fifty sachems of the confederacy were likewise sachems in their respective tribes, "and with the chiefs of these tribes formed the council of each, which was supreme over all matters pertaining to the tribe exclusively." The General Council could not convene itself, but could be convened by any one of the five tribal councils. The regular meeting was once a year in the autumn, in the valley of Onondaga, but in stirring times extra sessions were frequent. The proceedings were opened by an address from one of the sachems, "in the course of which he thanked the Great Spirit [i. e. Ioskeha, the sky-god] for sparing their lives and permitting them to meet together;" after this they were ready for business. It was proper for any orator from among the people to address the Council with arguments, and the debates were sometimes very long and elaborate. When it came to voting, the fifty sachems voted by tribes, each tribe counting as a unit, and unanimity was as imperative as in an English jury, so that one tribe could block the proceedings. The confederacy had no head-sachem, or civil chief-magistrate; but a military commander was indispensable, and, curiously enough, without being taught by the experience of a Tarquin, the Iroquois made this a dual office, like the Roman consulship. There were two permanent chieftainships, one in the Wolf, the other in the Turtle clan, and both in the Seneca tribe, because the western border was the most exposed to attack.[83] The chiefs were elected by the clan, and inducted into office by the General Council; their tenure was during life or good behaviour. This office never encroached upon the others in its powers, but an able warrior in this position could wield great influence. [Footnote 83: Somewhat on the same principle that in mediaeval Europe led an earl or count, commanding an exposed border district or _march_ to rise in power and importance and become a "margrave" [_mark_ + _graf_ = march-count] or "marquis." Compare the increase of sovereignty accorded to the earls of Chester and bishops of Durham as rulers of the two principal march counties of England.] [Sidenote: The "Long House."]