Urbanization of the territories beyond the walls of Bely Gorod (Boulevard Ring) is credited to Ivan Grozny. Ivan allocated these lands to Oprichnina, his own private domain. Very soon, Ivan's faithful associates resettled into "oprichnina" lands, thus present-day Ostozhenka, Prechistenka and Sivtsev Vrazhek streets initially developed as upper-class neighborhoods and retained this status ever since. Lanes in these neighborhoods (Mansurovsky, Khrushyovsky etc.) are named after original landlords. Ivan's son, childless Fyodor I, instituted extant Conception Monastery between Ostozhenka and Moskva River on the site of old Saint Alexis convent that perished in the Fire of Moscow (1547). Until the 1830s, frequent floods discouraged construction near the river, and the boundary of inhabited territories was 100–200 meters to the north from present-day embankment (see Vodootvodny Canal for more details). Legacy of 16th century survives in historical red and white chambers across Christ the Saviour, restored to their (perceived) original shape.