Russian push into the Amur basin begins
Labels: Cossacks, Amur basin, Qing frontierBy the mid-1600s, Russian Cossacks and officials moved southeast from Siberia into the Amur River basin, an area the Qing empire considered part of its frontier. These moves created competing claims over forts, tribute from local peoples, and control of river routes. This expansion set the stage for armed clashes and later border diplomacy.