is which gives unity
to the history of the Middle Ages. The Romans established a universal
empire by subjecting all countries to the authority of a single power.
The barbarians introduced into all a single system of law, and thus
became the instrument of a universal Church. The same spirit of freedom,
the same notions of the State, pervade all the _Leges Barbarorum_, and
all the polities they founded in Europe and Asia. They differ widely in
the surrounding conditions, in the state of society, in the degree of
advancement, in almost all external things. The principle common to them
all is to acknowledge the freedom of the Church as a corporation and a
proprietor, and in virtue of the principle of self-government to allow
religion to develop her influence in the State. The great migration
which terminated in the Norman conquests and in the Crusades gave the
dominion of the Latin world to the Teutonic chivalry, and to the Church
her proper place. All other countries sank into despotism, into schism,
and at last into barbarism, under the Tartars or the Turks. The union
between the Teutonic races and the Holy See was founded on their
political qualities more than on their religious fervour. In modern
times, the most pious Catholics have often tyrannised over the Church.
In the Middle Ages her liberty was often secured and respected where her
spiritual injunctions were least obeyed.

The growth of the feudal system coinciding with the general decay of
morals led, in the eleventh century, to new efforts of the Church to
preserve her freedom. The Holy See was delivered from the Roman factions
by the most illustrious of the emperors, and a series of German Popes
commenced the great reform. Other princes were unwilling to submit to
the authority of the imperial nominees, and the kings of France and
Castile showed symptoms of resistance, in which they were supported by
the heresy of Berengarius. The conduct of Henry IV. delivered the Church
from the patronage of the Empire, whilst the Normans defended her
against the Gallican tendencies and the feudal tyranny. In Sicily, the
Normans consented to hold their power from the Pope; and in Normandy,
Berengarius found a successful adversary, and the King of France a
vassal who compelled him to abandon his designs. The chaplain of the
Conqueror describes his government in terms which show how singularly it
fulfilled the conditions which the Church requires. He tells us that
William esta