Archimandrite Leonid (Kavelin Lev Aleksandrovich) (1822–1891) – philologist, bibliographer, archeologist, ethnographer. Correspondent Member of the Imperial Ac. of Sc. at the Department of Russian language and literature (1882), Correspondent Member of the Imperial Archeographic Commission (1863), Member of the Imperial Society of History and Russian Antiquities (1867). Specialist in the history of Russian Church, history of monasteries, medieval religion.
He studied at the Cadet Corps (till 1840); in 1852, he resigned and went to the Optina Hermitage as Novice. In 1857-1859, he served at the Russian Ecclesiastical Mission in Jerusalem; in 1859-1863 – in the Optina Hermitage; in 1863-1865, he was Head of the Russian Ecclesiastical Mission in Jerusalem. In 1865-1869, he was Rector of the Embassy church in Constantinople; in 1869-1877, he was Archimandrite of the Novo-Jerusalimsky Resurrection Monastery. Since 1877, he was Archimandrite of the Holy Trinity St Sergius Lavra.
Starting with the studies of some ecclesiastic antiquities (in 1847, he published ‘Historical Description of the Kozelsk Presentation Optina Hermitage’), he kept those studies till the end of his life. He prepared descriptions of many Russian monasteries, studied manuscripts and made a great input into the knowledge of Old Russian bookish tradition and medieval religion.