How did the church use the powers of excommunication and interdiction in maintaining its power?

The church used the powers of excommunication and interdiction to maintain its power because those that were excommunicated were banned from being involved with the church. They also could not receive the seven sacrament's, and if you didn't receive one of the sacraments before death, you were believed to go to hell.

pope john paul ii ( his real name is karol wojtyla) and lech walesa ( the leader of the solidarity movement ) were both born in poland.