Daguerreotype of Tsar Nicholas I on his death bed. The image shows the Tsar lying back on a pillow facing left with his body covered by a coat. A miniature painting from this daguerreotype is also in the Royal Collection (RCIN 420777).

Tsar Nicholas I, the third son of Tsar Paul I, succeeded the Russian throne in 1825 following the death of his eldest brother Alexander I and the renunciation of the throne by his second brother, Grand Duke Constantine. His aggressive interest in Turkey culminated in the Crimean War, which had not been concluded at the time of his death in 1855.

The Mouhot brothers were Henri (1826-61), French naturalist and explorer, and Charles (1828-95). Henri lived and worked as a teacher in St Petersburg between 1844 and 1854, the year in which he decided to travel around Europe with his brother, working together as daguerreotypists. While in The Hague in 1855, perhaps because of Henri's earlier connections with Russia, the brothers were given the task of reproducing the original daguerreotype (possibly by Sergei Levitsky) which had been sent to the Queen Dowager of the Netherlands, Anna Pavlovna of Russia (1795-1865), sister of Nicholas I, in June 1855, so that copies could be distributed to 'people of high birth and dignity' (Dr Wap (ed.), ‘Het photografisch etablissement der heeren Gebr. Mouhot, te ’s-Gravenhage’, Astrea: Maandschrift voor Schone Kunst, Wetenschap en Letteren, 5, p. 119). In 1856, the brothers moved to England where both married. Henri would then leave in 1858 to explore Indochina where he eventually died in 1861. He is chiefly remembered for his descriptions of the then virtually unknown ruins of Angkor, following the posthumous publications of his travel journals in 1863.