The accession to the throne of the second tsar of the Romanov dynasty, the sixteen-year-old Alexis Michailovich, took place without any incident. At home the dynasty was firmly established. In her foreign relations Russia maintained, during the first years of Alexis's reign (1645–76), the peace so dearly bought by Michael Feodorovich: in 1617 Moscow had resigned the Baltic littoral to Sweden, and in 1634 had ceded to Poland the districts of Smolensk and Novgorod-Seversk, the key to the Dnieper basin. Peace with the Ottoman Empire, overlord of the Tatars, had been assured by the abandonment of Azov (1642). Though Moscow endeavoured to utilise the Don Cossacks as a shield against Tatars and Turks, she was ever ready to disavow their actions in Constantinople, to avoid a serious attack upon her southern borderlands. With the exception of the region of the Don Cossacks, the European frontiers of Russia remained essentially the same as at the death of Ivan IV (1584).

In Siberia, on the other hand, the area under Russian sway had been greatly extended: in 1645 Poyarkov reached the Amur; in 1648 Okhotsk was founded on the Pacific shore and Dezhnev sailed around the northeastern tip of Asia. A few fortified strongpoints sufficed to maintain Russian rule over the sparse nomad population. In the remoter areas Moscow's actual authority was of course weak, but such political organisation as existed was from the start highly centralised; from 1637 onwards Siberia was governed from a special office in Moscow. The Russian settlers enjoyed neither political nor judicial autonomy, nor did they have any special colonial status. Siberia was treated as an Imperial province whose political structure evolved only gradually.