, but after 755 in May, whence it is called the Campus Maii) partly
for a military review on the eve of the summer campaign, partly for
deliberation on important matters of politics and justice. By the side
of this larger assembly, however, which contained in theory, if not in
practice, the whole body of Franks available for war, there had
developed, even before Carolingian times, a smaller body composed of the
magnates of the Empire, both lay and ecclesiastical. The germ of this
smaller body is to be found in the episcopal synods, which, afforced by
the attendance of lay magnates, came to be used by the king for the
settlement of national affairs. Under the Carolingians it was usual to
combine the assembly of magnates with the _generalis conventus_ of the
"field of May," and it was in this inner assembly, rather than in the
general body (whose approval was merely formal, and confined to matters
momentous enough to be referred to a general vote), that the centre of
power really lay. It is from the assembly of magnates that the diet of
medieval Germany springs. The general assembly became meaningless and
unnecessary, as the feudal array gradually superseded the old levy _en
masse_, in which each freeman had been liable to service; and after the
close of the 10th century it no longer existed.

The imperial diet (_Reichstag_) of the middle ages might sometimes
contain representatives of Italy, the _regnum Italicum_; but it was
practically always confined to the magnates of Germany, the _regnum
Teutonicum_. Upon occasion a summons to the diet might be sent even to
the knights, but the regular members were the princes (_Fursten_), both
lay and ecclesiastical. In the 13th century the seven electors began to
disengage themselves from the prince as a separate element, and the
Golden Bull (1356) made their separation complete; from the 14th century
onwards the nobles (both counts and other lords) are regarded as regular
members; while after 1250 the imperial and episcopal towns often appear
through their representatives. By the 14th century, therefore, the
originally homogeneous diet of princes is already, at any rate
practically if not yet in legal form, divided into three colleges--the
electors, the princes and nobles, and the representatives of the towns
(though, as we shall see, the latter can hardly be reckoned as regular
members until the century of the Reformation). Under the Hohenstaufen it
is still the rule that every me