After the conquest of Kazan in 1552 and the expansion of the Muscovite state further to the east, its newly acquired territories were subject to regular raids by the Nogai and Kalmyks. The southeast of modern Tatarstan bordered on the Nogai Horde and until the 1630s nomadic peoples ranged across the steppe. In the second half of the 17th century, Russia began building border fortifications, the so-called “lines” along the left bank of the Kama River. This period is associated with the construction of one of the first seven forts of the old Zakamskaya line, the Novosheshminskaya fortress.