What was the cause of the fued between Henry 4 and Pope gregory 7?

Read the excerpt from “pakistan’s malala.” "ziauddin had a revolutionary zeal and deep commitment to education," ellick said this week. "this charming little girl, she is a mini-version of him in many ways. she loves school, homework. whenever she would meet me she had a bookbag full of books." "she didn't have that idealistic activist attitude when she's 10 and 11, because who does? " ellick said. "her situation demanded that she grow up before she should have. she caught his contagious commitment and idealism." which detail best reflects how living in the taliban-ruled swat valley affected malala?