Catherine I acquired a public role through her marriage to Peter the Great, accompanying him on campaigns and becoming empress consort when Russia adopted the imperial title. Her coronation in Moscow in 1724 gave her a visible claim to authority. When Peter died in 1725 without completing a clear succession settlement, the guards and powerful supporters, especially Alexander Menshikov, helped secure her accession rather than that of Peter's young grandson.

Her reign lasted from 1725 to 1727. Catherine possessed the imperial title, but much of the conduct of government rested with experienced ministers and court allies. In 1726 she established the Supreme Privy Council, concentrating major decisions in a small body whose members included Menshikov and other senior figures. The council reduced the independent authority of earlier institutions and became central to the management of the state. Its creation was the principal administrative change of her short reign.

Catherine's government continued projects begun under Peter, including the opening of the Academy of Sciences at St Petersburg in 1725. Ministers managed European diplomacy and the financial burdens left by Peter's wars and reforms. Illness increasingly restricted her participation in affairs. At her death in 1727, the throne passed to Peter II, the grandson whose claims had been set aside two years earlier. Her accession established that a woman could hold Russia's imperial sovereignty in her own right.