What was the cause of the feud between henry iv and pope gregory vii? why was this feud important?

Henry lV and pope Gregory Vll. The crisis began when supporters of the gregorian reformed decided to rebel against simony by forcefully taking the power of investiture from the ruling secular power, the Holly Roman emperor and placing that power holly within the control of the church.

answer; i do believe that the (14th)fourteenth amendment is the correct answer

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