Fifty years before the birth of Christ, the Chinese Empire expelled the Huns, who turned to the West. The Huns conquered and scattered nations along the way. The scattered nations in turn conquered other nations.

In 475 the Roman Empire of the West fell before the invading nations. The entire Western world was composed of new nations. The leaders of the Church defended the people and strove to convert the invading barbarians.

In 452, as the Huns drew close to Rome, Pope Leo I went to meet Attila, the king of the Huns, and persuaded him not to invade Rome. Again in 455 Pope Leo went to meet Genseric, the leader of the Vandals, and convinced him to not burn Rome and to spare the lives of the people.

The Church sent missionaries to work among the new nations, and established churches and schools in the midst of the new people.

Even before the fall of the Roman Empire, St. Patrick (387-493) was already working tirelessly for the conversion of the Irish. He landed at Wicklow in 433, and laboured among the Irish for 60 years. On Easter Sunday in 433, St. Patrick preached to King Leoghaire and told him about heaven, a place more beautiful than the Irish lakes and hills. St. Patrick showed the people a shamrock: one stem with three leaves, and explained the mystery of the Trinity. St. Patrick built up a native clergy and established monasteries. Later, missionaries were sent forth from these monasteries to different parts of Europe to evangelize and to establish new monasteries and schools.

Among the English, St. Gregory the Great (540-604) became a Benedictine monk at the age of 34 and became Pope in 590. He selected 40 Benedictine monks and placed them under the leadership of a monk named Augustine, who became the first Archbishop of Canterbury. Within 50 years of the coming of the missionaries, the English had become Catholics.

Among the French, King Clovis was influenced by his Christian wife St. Clotilda, because in the battle with the Allemanni, Clovis had called on the God of Clotilda and had gained victory. Clovis was baptized by St. Remigius in 496. The conversion and victory of Clovis made France a united Catholic kingdom.

The monks from what is now Ireland, England, and Scotland evangelized the pagan tribes of central Europe in what is now Belgium, Holland, Germany, Austria, and Switzerland. The middle and northern parts of Germany were converted by St. Boniface. The Germans were great lovers of nature and practised nature worship. They held a great oak tree as sacred and called it the Tree of Thor. St. Boniface cut down the oak tree with an ax and out of it built the first Christian church. When nothing happened to St. Boniface, the faith of the pagans in Thor was shaken, and many people were converted to the Catholic faith.

St. Ansgar (died 865), a Benedictine monk from the Abbey of Corbie, evangelized Denmark and Sweden and baptized the King of Denmark in 826. He was the first Archbishop in Hamburg and Bremen and was the papal legate for the Scandinavian missions. St. Cyril (+869) and St. Methodius (+885) were brothers. In 863 they were sent as missionaries among the Slavs. St. Cyril became a monk in Rome and died there. St. Methodius was made Archbishop of the Slavs and received permission to use the Slavonic language in the liturgy. Both Sts. Cyril and Methodius translated the Gospels into Slavonic.

“The ultimate purpose of mission is none other than to make men share in the communion between the Father and the Son in their Spirit of love” (Pope John Paul II).

耶穌降生前五十年，中國漢帝驅逐匈奴，匈奴轉往西征，所向披靡，粉碎了歐洲諸國。那些國的國民又轉移粉碎其他的國。公元475年，西羅馬帝國瓦解，分裂諸地，紛紛自立為國；與此同時，聖教會一方面努力保護各民，另方面努力嘗試向入侵的外族，傳揚福音，使他們皈化。

公元452年，當匈奴大軍迫近羅馬，教宗聖良一世親入敵方，與匈奴王阿提拉會面，成功說服阿提拉無條件撤軍。公元455年，教宗聖良一世又成功說服萬達王，打消粉碎羅馬城的念頭，避免生靈塗炭。

由於很多新邦國的獨立，聖教會積極派遣傳教士到各處，既要傳揚福音，又建立聖堂、設立學校，服務新立國的人民。

早在羅馬帝國瓦解之前，公元433年，聖巴特利爵（387-493）登陸愛爾蘭，展開他六十年艱苦傳教之旅。433年復活節當天，聖巴特利爵向勞格耳王宣道，告訴他天堂比他那湖光山色的國土更美；聖巴特利爵又利用一片三葉草向愛爾蘭人，譬喻天主三位一體的奧秘。聖巴特利爵建立本地的神職班，又建立隱修院。後來，傳教士由這些隱修院出發，到愛爾蘭以外的歐洲各地，建立更多的修院和學校，廣傳福音！

教宗聖額我略一世（540-604）在三十五歲時，成了本篤會會士，公元590年當選教宗。他挑選了四十名本篤會會士，由聖奧斯定（稍後成了英國坎達伯理總主教）帶領，到英國傳教；五十年內，英國成為天主教國家。

法國克羅維斯國王，娶信奉天主教的克羅蒂達為妻。一次與敵軍交鋒時，克羅維斯國王向「克羅蒂達的天主」呼求，結果獲得勝利。公元496年，克羅維斯國王從聖雷米奇墨手中領受聖洗聖事，法國於是成了天主教國家。

從愛爾蘭、英國及蘇格蘭隱修院出發的傳教士，滲入異教的國土，包括今日的比利時，荷蘭、德國、奧地利和瑞士。中部和北部的德國日以曼民族，經聖博義的傳道而皈化：當時的日以曼民族，崇拜大自然生物，聖博義親自砍下他們的「神聖橡樹」，將木頭建成聖堂，而聖博義居然未受「神樹」懲罰，使到很多人驚訝，甘心皈依聖教。

聖安斯卡（+865）是來自榷比大修院的本篤會會士，他到丹麥和瑞典傳教，並在公元826年給丹麥國王付洗。聖安斯卡曾任漢堡及伯汶的總主教，且是北歐區的宗座代表。

聖啟祿（+869）和聖默道（+885）是兄弟，在公元863年期間，同被派到斯拉夫傳教，他們創造了斯拉夫的字母，用斯拉夫文翻譯了福音。聖啟祿在羅馬隱修和離世；聖默道成了斯拉夫總主教，後被授權在禮儀中使用斯拉夫文。

真福教宗若望保祿二世言道：「傳教最終目的無他，只為讓眾人能分享聖父和聖子在聖神的愛中的共融。」