when the
community became more thoroughly amalgamated and inwardly united,
that this usage was departed from and the selection of the senators
was left entirely to the free judgment of the king, so that he was
only regarded as failing in his duty when he omitted to fill up
vacancies.

Prerogatives of the Senate. The -Interregnum-

The prerogatives of this council of elders were based on the view
that the rule over the community composed of clans rightfully
belonged to the collective clan-elders, although in accordance
with the monarchical principle of the Romans, which already found
so stern an expression in the household, that rule could only be
exercised for the time being by one of these elders, namely the
king. Every member of the senate accordingly was as such, not in
practice but in prerogative, likewise king of the community; and
therefore his insignia, though inferior to those of the king, were
of a similar character: he wore the red shoe like the king; only
that of the king was higher and more handsome than that of the
senator. On this ground, moreover, as was already mentioned, the
royal power in the Roman community could never be left vacant When
the king died, the elders at once took his place and exercised the
prerogatives of regal power. According to the immutable principle
however that only one can be master at a time, even now it was only
one of them that ruled, and such an "interim king" (-interrex-) was
distinguished from the king nominated for life simply in respect
to the duration, not in respect to the plenitude, of his authority.
The duration of the office of -interrex- was fixed for the individual
holders at not more than five days; it circulated accordingly among
the senators on the footing that, until the royal office was again
permanently filled up, the temporary holder at the expiry of that
term nominated a successor to himself, likewise for five days,
agreeably to the order of succession fixed by lot. There was not,
as may readily be conceived, any declaration of allegiance to the
-interrex- on the part of the community. Nevertheless the -interrex-
was entitled and bound not merely to perform all the official acts
otherwise pertaining to the king, but even to nominate a king for
life-- with the single exception, that this latter right was not
vested in the first who held the office, presumably because the
first was regarded as defectively appointed inasmuch as he was not
nomina