The name Cyrillus or Cyril or Cyryl is derived from Greek ???????? (Kyrillos - lordly, masterful), related to kyrios - lord, master.
It is the name of several historic figures:
The former of the Saints Cyril and Methodius, a 9th century Byzantine Greek monk, scholar, theologian, linguist and apostle to the Slavs, believed to have co-invented the Glagolitic alphabet, the first Slavic alphabet, and translated the Bible into a Slavic language referred to as Old Church Slavonic
Cyril of Turaw, 12th century Belarusian Orthodox Christian bishop and theologian