863 · Great Moravia (modern Czech Republic / Slovakia)
Cyril and Methodius Bring Christianity to the Slavic Peoples
In 863, two Greek brothers from Thessalonica — Cyril and Methodius — were sent to Moravia to preach the Gospel in the language of the people, creating a new alphabet and translating the liturgy into Slavonic, laying the foundation for Christianity across Eastern Europe.
Prince Rastislav of Great Moravia had a problem. He wanted Christian missionaries, but he did not want the ones being sent by Frankish bishops, who came with political strings attached. So he wrote to the Byzantine Emperor Michael III and asked for teachers who could preach in the Slavic language. The emperor turned to two brothers from Thessalonica who already knew Slavic — Constantine (who would take the name Cyril shortly before his death) and Methodius. Before leaving, Cyril did something that changed the course of European civilization. He created an alphabet for the Slavic language. There was no way to write Slavonic at the time, so Cyril invented one — the Glagolitic script, which his students would later develop into what we now call the Cyrillic alphabet. He then translated the Gospels and the liturgy into this new written language. The brothers arrived in Moravia in 863 and began preaching, teaching, and celebrating the liturgy in Slavonic. This immediately caused conflict with Frankish clergy who insisted that the liturgy could only be celebrated in Latin, Greek, or Hebrew. Cyril and Methodius traveled to Rome to defend their approach. Pope Adrian II sided with them, approving the use of Slavonic in the liturgy — a remarkable decision that would not be repeated for the Latin rite until Vatican II, over a thousand years later. Cyril died in Rome in 869 and was buried in the Basilica of San Clemente. Methodius returned to his mission and continued working until his death in 885, facing constant opposition from Frankish bishops. After Methodius died, their disciples were expelled from Moravia but carried the Slavonic liturgy to Bulgaria, Serbia, and eventually Russia. The brothers had started something that could not be stopped. They are honored today as the co-patron saints of Europe.
Why it matters
Created the written Slavonic language and brought Christianity to the Slavic peoples, shaping the religious and cultural identity of Eastern Europe for over a millennium and earning recognition as co-patron saints of Europe.
What Happened
In 863, the brothers Cyril and Methodius were sent from Constantinople to Great Moravia to evangelize the Slavic peoples. Cyril invented an alphabet for the Slavonic language and translated the Gospels and liturgical texts. They celebrated the liturgy in Slavonic, defended this practice before Pope Adrian II in Rome, and received papal approval. After Cyril's death in Rome in 869, Methodius continued the mission until 885. Their disciples carried the Slavonic Christian tradition to Bulgaria, Serbia, and Russia.
Why It Still Matters
Cyril and Methodius established the principle that the Gospel should be preached and the liturgy celebrated in languages people actually speak — a principle the Western Church would not fully embrace until Vatican II. The alphabet Cyril created is still used by hundreds of millions of people. Their mission shaped the Christian identity of Russia, Ukraine, Serbia, Bulgaria, and other Slavic nations. Pope John Paul II named them co-patron saints of Europe alongside Benedict of Nursia.