The Growth of Christianity in Europe

The Growth of Medieval Christendom's Boundaries in Europe

Conversion of the Nomadic Tribes to Christianity

The rescript of Milan: an important turning point
After suffering centuries of persecution from Rome, Christianity eventually became one of the state religions of the Roman Empire. Emperor Constantine the Great declared his faith in Christianity and began to support it. In the year 313 A.D., together with Licinius, Constantine drafted the Milan program of toleration and sent it to the governors of the eastern provinces. This was the rescript of Milan. This rescript accorded Christianity full equality with the other religions of the Roman Empire. Christianity was then able to expand and develop itself as a religion: through internal organizations brought about by ecumenical councils such as Nicea (325 A.D.) and Ephesus (431 A.D.); through the exemplary leadership of Sts. Ambrose, Augustine, Jerome, and Gregory the Great; and through the growth of the monastic movement under the influence of the St. Benedict, the Father of Western Monasticism.
Conquering nomadic tribes threaten Christianity
Just as Christian civilization was firmly rooting itself in many territories of the Roman Empire, a tide of nomads from the steppes came like a great wave on the Christian Roman culture and attempted to overwhelm it. These conquering nomads originated in Eastern Asia, round the periphery of China. One of these nomadic tribes were the Turco-Mongols, the main element of which were the Huns. Then there were the Alans who located themselves towards the Caspian and the Caucasus. Farther north, spaced out along the Baltic coast, lay the Finns, the Lithuanians, and the Slavs. Then the vast area stretching from the Vistula to the Rhine was peopled by various Germanic groups - the Goths, who had moved down into the Ukraine; the "shining" Ostrogoths to the east; and the "wise" Visigoths to the west. There were also Vandals on the Danube, Angles in Schleswig, Lombards on the banks of the Elbe, Saxons on the Weser, Alamanni on the Main, and a spearhead of Burgundians and Franks on the Rhine. Christian civilization was being threatened by what many historians term as the "barbarian flood".
Catholicism entering into the Middle Ages
At this time, historians record also the beginning of the fall of the Western Roman Empire at about 476 A.D. And the migration of the conquering nomadic tribes was part of the turning point to the beginning of a new age - the Middle or Medieval Age. The only bond that linked the period before the fall of the Western Empire and the beginning of the Middle Ages was the Catholic Church. What is epochal and very important in the growth of Medieval Christendom's boundaries was the successive conversion of the Germanic tribes. King Clovis of the Salian Franks was baptized in 496 A.D. This began the amalgation of the Franks to Catholic Christianity. The culture of the Franks and the religious customs of the Catholic faith merged.
Conversion of more Germanic tribes, the Slavs, and the Baltic peoples
In the sixth to the seventh centuries, Catholicism also was accepted by the Lombards, the Angles, the Saxons, and the Visigoths. The conversion of the Frisians and the Hessian Germans then occurred in the seventh and the eighth centuries. The conversion of the northern Germans and the western Slavs took place during the ninth, tenth, and eleventh centuries. And finally, the Baltic peoples were incorporated into Christendom in the thirteenth and the fourteenth centuries.
The Christianization of Scandinavia
The Scandinavian kings were very instrumental in the Christianization of Denmark, Norway, and Sweden. Danish King Sven (d. 1014) and his son Canute (d. 1035) brought missionaries into Denmark, while two Norwegian kings, both named Olaf, did the same for Norway in the eleventh century. Although the Swedes resisted conversion at first, with the conversion of their neighbors Denmark, Norway, and Poland, pressures mounted, and by the end of the eleventh century, most of the resistance was overcome. In 1164 A.D., the Pope made Uppsala a metropolitan see for all Sweden.
Sts. Cyril and Methodius converts the Slavs
During the great migrations of the nomadic tribes, the Slavs spread across central Europe and occupied the wide stretch of land from the Dnieper to the Elbe and Saale rivers, including Bohemia. It was during these times that St. Cyril (d. 869) and St. Methodius (d. 885) became missionaries of the Christian faith to the Slavs in Moravia in the ninth century. St. Cyril invented the Slavonic alphabet by combining Greek letters with some new ones in order to provide the Slavs with a liturgical language.
Bohemia, Poland and Hungary become Christian states
Christianity made real progress among the Slavic peoples when the Bohemian princes looked to Germany for protection against the fierce Magyar invaders. Their alliance with Germany therefore influenced them toward Christianity. In 973 A.D., an episcopate in Bohemia was founded at Prague. From here, Christianity spread among the Poles, whose renowned Prince Mieszko (d. 990) firmly established the Polish Kingdom and presented his realm to the Pope. A papal charter gave Poland its own ecclesiastical organization - bringing Poland into the Western orbit. The conversion of the Hungarians was likewise carried out during the tenth and eleventh centuries.
The Christianization of Russia, Livonia, Prussia and Lithuania
For a time it looked as if Russia would follow Poland and Hungary into the papal orbit. Russia was already receiving Christian missionaries from both the East and the West as early as the ninth century. But it was only under Vladimir (d. 1015) that Christianity was fully adopted. This Russian prince sought counsel with emissaries of the Pope and the Patriarch as well as with Moslems and Jews. After weighing all the pros and cons, he finally decided to accept baptism in the Byzantine Church. After Russia, the last Eastern Europeans to accept Christianity were the Baltic people of Livonia, Prussia, and Lithuania in the thirteenth and fourteenth centuries.
References of this article

• A History of the Church, by Franzen and Dolan
• A Concise History of the Catholic Church, by Thomas Bokenkotter
• The History of the World in Two Hundred and Forty Pages, by Rene Sedillot