The upper consists of princes of the grand-ducal family, heads of mediatized houses, the head of the Roman Catholic and the superintendent of the Protestant church, the chancellor of the university, two elected representatives of the land-owning nobility, and twelve members nominated by the grand duke.
The lands of both these princes are now mediatized.
In its modern usage it is practically confined to the money endowment given to the younger children of reigning or mediatized houses in Germany and Austria, which reverts to the state or to the head of the family on the extinction of the line of the original grantee.
This was first done on a large scale in 1803, when by a recess of the imperial diet many of the smaller fiefs were mediatized, in order to compensate those German princes who had been forced to cede their territories on the left bank of the Rhine to France.
On the other hand, at Aix-la-Chapelle (1818) the powers, in response to the representations of the aggrieved parties, admonished the German sovereigns to respect the rights of the mediatized princes subject to them.