By Slavic origin, he was a disciple of the Holy Equal-to-the-Apostles Methodius (+ 885; May 11/24) and Cyril (+ 869; May 11/24) and helped the holy brothers in the enlightenment of the Slavic people and in their struggle for the purity of Orthodoxy in Moravia. After the expulsion from Moravia, the Slavic confessors of St. Peter the Great. Angelyar, Kliment and Nahum arrived in Bulgaria, where they were greeted with honor and asked to introduce worship in the Slavic language. The enlighteners immediately began to study Slavic books collected by the Bulgarian nobility.
Soon after, Saint Angelar died, and Saint Clement was appointed to teach in Kutmichivica, a region in southwestern Macedonia. In the Eastern Church, a worthy person, known for his pious life and possessing the gift of speech, was elected to the position of teacher. Saint Clement was still in Moravia with the rank of "qualified teachers."
In Bulgaria, St. Clement served as a teacher until 893. He organized, first of all, a school at the princely court, which reached a high level during the reign of Simeon, and in southwestern Macedonia he created schools separately for adults and children. St. Clement taught children to read and write. The total number of his disciples was huge: only 3,500 people are known to belong to the clergy. In 893, St. Clement was elevated to the rank of bishop of Dremvitsa, or Velitsa, and his place was taken by St. Naum.
St. Clement was the first Bulgarian hierarch to serve, preach, and write in the Slavic language. The saint labored for the glory of God until a very old age, fulfilling both his episcopal ministry and continuing his translation work. He peacefully passed away to the Lord in 916. The body of the saint was buried in the Ohrid Panteleimon Monastery founded by him.
St. Clement is considered the first Slavic writer. He not only continued the translation work begun by Saints Cyril and Methodius, but also left his writings, the first examples of Slavic spiritual literature.