Final answer:
When the Pope places a kingdom under 'interdict,' he imposes a ban on religious services and sacraments in that kingdom. It is a way for the Church to put pressure on a monarch who acted against its interests.
Step-by-step explanation:
When the Pope places a kingdom under 'interdict,' it means that he imposes a ban on religious services and sacraments within that kingdom. This includes the withholding of basic spiritual rites such as baptisms, marriages, and last rites. The purpose of the interdict was to exert pressure on a monarch or ruler who had acted against the interests of the Church, as well as to punish the subjects of that kingdom and to push them to pressure their ruler to submit to the Church's authority.