Lombard kings, we find Charlemagne,[85] on suspicion of infidelity to
his government, having sent to him and retaining as prisoners the
bishops "Civitatis Pisanae seu Lencanae" and Pottoni, Abbot of the
monastery of Volturno; and Lewis the Pious[86] sends into exile
"Ermoldo Nigello Abatis," and in the year 818 several other bishops,
including Anselmus "Mediolanensis Archiepiscopus," "Wolfoldus
Cremonensis" and "Theodolphus Amelianensis."[87] None of these
restrictions and limitations, however, although they arose chiefly
from the strong opposition always existing between the local temporal
rulers of the people and their spiritual rulers, could hinder the
bishops from occupying that important position of mediators and of
protectors of the people which we have ascribed to them.

Turning now to a consideration of the earliest steps which may be said
to have cleared the way for the political power of the bishops, we are
met by a subject which, though of great interest in itself, is not
sufficiently a part of this investigation for us to do more than
indicate the lines of its progress. This subject is the development of
the practice of giving certain immunities and privileges to churches
and monasteries, adopted by the Frankish kings, faithful sons of the
church, and then followed by all their royal and imperial successors.
In considering the important influence exercised by these immunities
on the development of the espiscopal power and the effects of this on
the growth of the communes, there are two essential facts which we
must always keep prominently in mind. In the first place we must
remember that the granting of immunities was a question of privilege
to particular individuals or ecclesiastical institutions, and not a
universal grant which affected in an equal degree all the dioceses of
the realm. This led to the marked differences in rank and importance
which existed between the various bishoprics, and in the tenth