Simony, in Canon Law, is any deliberate act or premeditated will or desire to buy such things which are spiritual, or of a spiritual nature, by using something which is of a temporal nature for the purchase thereof. In general terms it is defined to be a conversion of a spiritual thing or of a spiritual nature by giving something which is temporal.
The sin of Simony, was the sale of Church offices or sacraments for money. The Papal Reform movement wanted completely to root out this sin and end the immoral practice of simony. Their reforming zeal was based on Canon Law. The reforming popes, and Gregory VII in particular, saw it as their responsibility to prohibit and end the investiture of bishops by lay authorities. The investiture of bishops had long been a custom amongst lay rulers, who claimed that it was their right to install and grant newly elected prelates in and with their land to the secular rights and prperoperties of their sees. This practice had evolved and corrupted over time from one of the king's right not only to invest a newly elected bishop with his regalia but transformed into the king assumed the power to select teh candidate make the appointment of the new bishop in the first place. This went completely against Canon Law and displacing the process of canonical election by the dean and chapter of the cathedral, for the office of bishop was often sold by the king to the highest bidder or to those who could be relied upon for financial, or political support.
This serious offence against the Church is defined in the Corpus Juris Canonici [Body of Canon Law] in the Decretum pars. ii. causa i., in various quaestiones.
Let him be deprived of the honour who obtains a church by means of money.
Let the bishop be suspended from office if found selling benefits or ecclesiastical office.
First Lateran Council 1123
Summary. Ordinations and promotions made for pecuniary considerations are devoid of every dignity.
Text. Following the example of the holy fathers and recognizing the obligation of our office, we absolutely forbid in virtue of the authority of the Apostolic See that anyone be ordained or promoted for money in the Church of God. Has anyone thus secured ordination or promotion in the Church, the rank acquired shall be devoid of every dignity.
(1912). Simony. In The Catholic Encyclopedia. New York: Robert Appleton Company.
Everett U. Crosby (2003). Bishop and Chapter in Twelfth-Century England: A Study of the 'Mensa Episcopalis'. Cambridge University Press. pp. 324–. ISBN 978-0-521-52184-0.Price paid to the king to be made a Bishop= £500
Gilbert Foliot and His Letters. inspeximus: CUP Archive. pp. 137–
Inspeximus [we have inspected] is the formal document by which a king confirms the grant given in previous charters by prior kings of lands and properties belonging to a bishopric to a new bishop. The king inspects for a fee .