King Arthur's table in the Arthurian legend, around which he and his knights congregate, all having equal status since the table has no head.
The council that governed the ancient Roman Republic.
Any of several legislative bodies. (In countries which have multiple legislative bodies, the Senate is often the more senior.)
The Senate of Canada; the upper house of the Canadian parliament; "the Senate".
The United States Senate.
The upper legislative body of many of the states of the United States.