Early Christian Martyrs

I believe Cyril\Kyril was sent out by the Patriarch of Constaninopol\Byzantium, not the Patriarch of Rome.

 

You are correct. Both Cyril and Methodius were sent by the patriarch and emperor at the request of the Moravians prince.

Cyril died not longer after visiting Rome for the first time; Methodius was ordained a priest by the pope and sent to Moravia, where he was in conflict with the German Latin Rite bishops, who kept him in prison for more than two years.

Although feast days of Cyril and Methodius were observed in the Moravian and Bohemian churches for centuries, it was not until 1880 that the pope got around to making their feast days observed throughout the entire Latin Rite. They were regarded as saints among the Orthodox beginning in the 11th century and are considered ἰσαπόστολος, or equals to the apostles.