A comprehensive history of the Sino-Russian border, one of the longest and most important land borders in the world The Sino-Russian border, once the world's longest land border, has received scant attention in histories about the margins of empires. Beyond the Steppe Frontier rectifies this by exploring the demarcation's remarkable transformation-from a vaguely marked frontier in the seventeenth century to its twentieth-century incarnation as a tightly patrolled barrier girded by watchtowers, barbed wire, and border guards.