What did the argument between king henry and pope gregory VII demonstrate

The conflict between Henry IV and Gregory VII concerned the question of who got to appoint local church officials. Henry believed that, as king, he had the right to appoint the bishops of the German church. This was known as lay investiture.

the conditions that made the byzantine empire vulnerable to attacks by the muslin turks were the sack of constantinople by western crusaders, the conquests of the sultanate of rum, presence of rival kingdoms and finally the set up of fiefdoms at the empire which were owned by the ghazis (turkish warriors).

some american cities felt workers were being oppressed by business monopolies