During the Middle Ages is when religion had political power. During this time, it was undoubtedly the Catholic religion. It controlled life, set the rules for life, etc. During this time though, the religion became corrupt. People started making their own religion, protesting Catholicism. And thus, Protestantism was born. Major religions such as Anglican, Lutheran, and Calvinism came about.
Rome controlled most of Europe and the east. They were the government, the builders, and protection of Europe.
The Roman Catholic Church
The group with took over most of Europe after the fall of the western part of the Roman Empire eventually were the Franks. They did not do so immediately. They took over gradually.
clergy
romans
The Vikings.
The group that included Ostrogoths, Visigoths, Franks, and Vandals is known as the Germanic peoples. These were various tribes of Germanic origin that played significant roles in the decline of the Western Roman Empire and the subsequent formation of Medieval Europe.
Well there are four regions in Europe: Northern, Western, Southern, and Eastern Europe. You could break these into some sort of ethnic group, such as Western European.
the nations of western europe
The people who took refuge in Poland during the Late Middle Ages were Jews form various parts of Western Europe. There is a link to an article on the history of Jews in medieval Poland below.
germoney
the united nations
roman
The roman catholic church.