Maternal great-great grandfather of the composer (b. ca. 1732; d. 8/19 January 1783), born Ivan Ivanovich Popov (Иван Иванович Попов), also known as Ioann Ioannovich Popov (Иоанн Иоаннович Попов).
He was Deacon at the Church of Saint Nikita in Moscow; later a regimental with the second Moscow Infantry Regiment, which participated in the Prussian War (1757–1763), before being stationed in Kiev (1763–1770). In 1770, he became Priest at the Church of Saint Sergiev in Saint Petersburg, where he remained until his death.
Ivan Popov died from consumption on 8/19 January 1783, and was buried at the Okhtensky Cemetery in Saint Petersburg.