Traditionally, the painting is attributed to Louis Caravacque. However, through the technical research conducted and comparison of the work to classic paintings by Caravacque, it was determined that there is a difference in brushwork. It is very likely that the portrait was created by Johann Gottfried Tannauer in the middle of the 1710s when Karl Leopold, Duke of Mecklenburg-Schwerin was proposing to Catherine Ioannovna.

Catherine Ioannovna (October 29, 1691 – June 14, 1733)
Tsarevna, daughter of Tsar Ioann V Alexeyevich, elder sister of Empress Anna Ioannovna. In 1716 she married Karl Leopold, Duke of Mecklenburg-Schwerin (November 26, 1678 – November 28, 1747). In 1722 she came back to Russia together with her daughter, Anna Leopoldovna (December 7, 1718 – March 19, 1746), who would give birth to Emperor Ioann VI (August 12, 1740 – July 5, 1764) and become the regent of Russia for the period of his reign (from October, 1740 to November 25, 1741).

Caravaque Louis

Caravaque, Louis
1684, Marseilles – 1754, St Petersburg
Painter, portraitist, designer, miniaturist, graphic artist. Member of the third generation of French painters working in Marseilles and Tulon. Invited to Russia by Peter the Great (1715). Lived and worked in St Petersburg (from 1716). Painted portraits of Peter the Great and members of the Imperial family. Painted murals and headed painting work in Peterhof and in the Summer Palace in St Petersburg. Compiled festival projects for the Imperial court. Court artist with an exclusive right to paint Imperial portraits during the reign of Empress Anna Ioannovna (1730–1740) and Empress Elizabeth Petrovna (1741–1761). Taught painting to Ivan Vishnyakov, Alexei Antropov and Mikhail Zakharov.