Lebedev Aleksey (1845‒1908) – historian of the Church, specialist in the Byzantine studies.

He was born in the family of a priest, learnt at the Perervinskoe Spiritual School, and at the Moscow Seminary. In 1870, he graduated from the Moscow Spiritual Academy and started to work there, teaching ecclesiastic history. Since 1875, he was Ass. Professor; since 1879 – Full Professor; he worked there till 1905.

At the defense of his Doctor thesis ‘Ecumenical Councils of the Fourth and Fifth centuries: A Survey of Their Dogmatic Activity in the Context of the Trends of the Schools of Alexandria and Antiochia’, there was a scandal mentioned in the media. His opponent, Archpriest A. M. Ivantsov-Platonov – obviously, with a support of Rector of the Academy, accused L. in sympathy to Arianism, praising heretics, and even in the proximity to the views of ‘Rationalist Bauer’. It created L a reputation of Liberal.

In 1896-1908, he was Professor of the Chair of Ecclesiastic History at the Historical and Philological Faculty of the Moscow University. He put ecclesiastic history higher than theology, and in his works on all the long history of East Orthodoxy presented the newest achievements of European ecclesiastic history to his readers.