He was born as Ivan Ilyich Sergiyev in 1829. From 1855, he served as a priest in St. Andrew's cathedral in Kronstadt. Here, he greatly committed himself to charity, especially for those who were remote from the church, and traveled extensively throughout the Russian empire. He was a member of the right extremist movement Sojuz Russkogo Naroda (Alliance of the Russian people) but did not commit himself politically. He was already greatly venerated at the time he died. He was glorified by the Russian Orthodox Church Outside of Russia in 1964 and by the Russian Orthodox Church on June 8, 1990. The second largest monastery in St. Petersburg (by community size) is dedicated to St. John of Kronstadt.