The papal reaction to lay investiture
(the interference of temporal rulers in the appointment and installation of bishops and abbots) in the 11th century liberated the church from political domination, but also laid the foundation for the canonically inflated papacy of the second millennium.
That said, the overall structure--relations with regional political and ecclesiastical authorities followed by analyses of Gregory's position on reform issues, the nature of papal authority, monasticism, etc.--does make for repetition in that issues such as simony, lay investiture
, or obedience covered in one context are discussed later, often with the same examples.
The debate inevitably turned on the practice of lay investiture
, according to which an emperor or king filled a vacant episcopal see with a candidate of his choice.
It is naive to suppose, as has commonly been done, that the supporters of Henry IV and the German court were opponents of reform', which was never the root of the hostility between Gregory and Henry's advisers: |It was not the details of the "reform programme", such as canonical elections, prohibition of clerical marriage, simony, or lay investiture
which created the irreconcilable differences but the resistance of Henry and his supporters to the demands of the popes for absolute obedience.' When Germany was plunged into civil war, Gregory was certainly more interested in the role of arbiter than in "reforms"'.
His reign was marked by the great struggle between empire and papacy over the question of lay investiture
. Hitherto the emperors had filled the ecclesiastical positions within their dominions at their pleasure.