The Adelsraad was an elected body in the legislature of Shireroth that was elected by the adult citizens (i.e. denizens of noble blood and their legal equal spouses). Between 1671 and 1717 AN it didn't meet as domestic problems shifted the (remnants of the) Imperial Government's attention to other pressing matters. Its elected representatives, local nobles, retreated to their mansions and domains, from which they handled their affairs. The last election of the Adelsraad, prior to the 1717 general elections was held in 1669.
While the current Adelsraad only emerged in the mid-17th century, the term was already used in 1574 by Kaiser Magni I (Imperial Decree 474): "There shall be created a legislative body consisting of the Dukes of the major subdivisions, called the Adelsraad, whose powers shall be defined at a later time, due to their nature requiring an amendment to the Imperial Charter."
The composition and goals of the present-day council has, however, nothing to do with the earliest attempts to establish it.