The unity of the Empire was expressed not only in the person of the emperor, but in the Diet which met at different places at frequent intervals.

Its authority, though on the whole increasing, was small.
With no imperial system of taxation, no professional army and no centralized administration, the real power of the emperor dwindled.
Such as it was he derived it from the fact that he was always elected from one of the great houses.

Since 1438 the Hapsburgs, Archdukes of Austria, had held the imperial office.

Since 1495 there was also an imperial supreme court of arbitration.

[Sidenote: 1495] The first imperial tax was levied in 1422 to equip a force against the Hussites.
In the fifteenth century also the rudiments of a central administration were laid in the division of the realm into ten "circles," and the levy of a small number of soldiers.