The most conspicuous difference between the interdict and the (more famous) excommunication during the Middle Ages is that the former was imposed upon the area while the latter was sentenced to the person. Hereby I cite an excerpt of the papal letter of Innocent III in Oct 6th of 1198, addressed to all the clergy (archbishop, bishops, and the other prelates) in Norway, below:
Vniuersitati uestre per apostolica scripta districte precipiendo mandamus quatinus uniuersum Norwagie populum diligentius moneatis ne ipsum ulterius sequi presumant. aut ei prestare auxilium uel fauorem. Alioquin uniuersos sequaces ipsius excommunicationis nuncietis sententia innodatos. et claudentes ecclesias et nullum in tota terra Norwagica que ipsum sequitur sacramentum ecclesiasticum preter baptismata paruulorum et penitentias morientium celebrantes fautoribus eius decedentibus sepulturam ecclesiasticam denegetis.
‘(My very rough translation) I order with this papal mandate that all of the people in Norway should be more careful neither to follow him [King Sverre of Norway] any further nor to support him with any help or favor. All his followers should also be sentenced to be excommunicated, and the church should be closed. No place in the land of Norway should not held the ecclesiastical sacraments for him, except for the baptism of child and the unction on deathbed, and further, we forbid his dying supporters to be buried in the church graveyard (Diplomatartium Norvegicum VI-7a: Potthast nr. 386)’.
Innocent III was also known to impose similar interdict on the kingdom of England under the reign of King John in the beginning of the 13th century, as summarized in Southern’s classic book on the medieval church as following: ‘During the whole of this time [4 years excommunication] and for eighteen months previously, his kingdom was under an interdict and all the ordinary service of the churches – marriages, masses, Christian burials, everything except baptism and the last rites – were suspended (Southern 1970: 20)’. These two accounts share the same details: The interdict in the High Middle Ages (ca. 1200) was basically a suspension of the five of seven sacraments, namely the confirmation, the matrimony, the confession, the eucharist, and the consecration, on the specified area.
In both cases [against King Sverre and Norway and King John of England], this church ban was employed together with more personal one, excommunication, so it is not so easy to determine to what extent this ban alone was effective. Both Sverre and John could withstand under an interdict more than 4 years. Southern and Turner notes that King John rather succeeded in keeping order of the religious life in England, at least in the first phase of the interdict (Southern 1970: 20f.; Turner 1994: esp. 160-63). Neither Krag consider the interdict upon ‘Norway’ actually as effective, for some ambiguity in the interdict/ excommunication mandate of the Pope (Krag 2005: 171-73). Thus, this measure itself did not always have an immediate coercive force to subjugate such disobedient rulers like Sverre and John alone. Krag acknowledges some middle to long-term effect for the interdict, though, and compares it as ‘the war that the king could not finally win’: While the ruler could oppose the short-term impact of the measure by force, it did not keep more and more rather ‘neutral’ prelates from estranging from him, and the situation increasingly worsened towards the end of his reign. The efficiency of the interdict should be perhaps measured from such a point of view.
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