Elisabeth Katharina Christine of Mecklenburg-Schwerin in 1722 had arrived in Russia with her mother, who had escaped and separated from her father, Charles Leopold, the Duke of Mecklenburg-Schwerin: her mother, Tsarevna Catherine of Russia (sister of Empress Anna), had been considered as a candidate to the throne in 1730, but her aunt had been chosen instead.

Elisabeth in 1733 had converted to the Orthodox religion and been given the name Anna Leopoldovna, which had made her acceptable as an heir to the throne.

She had in 1739 married Anthony Ulrich (1714–1776), son of Ferdinand Albert, Duke of Brunswick-Wolfenbüttel: he had been taken to Russia already in 1733, so that she could get to know him.

The empress Anna had on October 5, 1740, adopted their newborn son Ivan and proclaimed him heir to the Russian throne.

The empress dies on October 28, a few days after this proclamation, leaving directions regarding the succession, and appointing her favorite Ernest Biron, Duke of Courland, as regent.