Final answer:
During 600 C.E. to 1450 C.E., there were changes in the political structure of Christianity, including the rise of nation-states and monarchs in Western Europe, the Protestant Reformation, and internal power struggles within the Church.
Step-by-step explanation:
During the period from 600 C.E. to 1450 C.E., there were several changes in the political structure of Christianity. One significant change was the emergence of nation-states and the increasing power of monarchs in Western Europe. These monarchs sought to weaken the authority of the Pope and increase their own power. Another change was the Protestant Reformation, which challenged the authority of the Roman Catholic Church and led to the formation of new Christian sects throughout Europe. Additionally, there were internal power struggles within the Church, with popes and cardinals often behaving more like political leaders than spiritual leaders.