Few people know that less than 200 years ago, there were no sisters of mercy in wars; they only appeared in the 19th century. The first Russian association of sisters of mercy was the "Holy Trinity Community," founded on March 9, 1844. The founding day is considered to be the founding meeting, which took place in the palace of Prince Peter Georgievich of Oldenburg. The initiators of the society's creation were Grand Duchesses Maria and Alexandra Nikolaevna, daughters of Emperor Nicholas I.

When creating the first Russian community, they took as a model a similar association in Warsaw, which Princess Oldenburg visited a year prior. She also attended the meeting on March 9, 1844. Prince Oldenburg himself was a well-known benefactor and a nephew of the Russian monarch.

The community initially helped those in need and paid attention to children. In 1841, under the patronage of the princess, the "Princess Therese of Oldenburg Institute" was established for the education of girls. The emperor's daughters also actively participated in charity work: under the patronage of Maria Nikolaevna, two night shelters operated. Therefore, the creation of a new charitable institution was not a surprise. During the Crimean War, the sisters of mercy from the "Holy Trinity Society" assisted in hospitals, and in the next war with Turkey, the first group of sisters was sent to the front to help the wounded. This caused shock, as the red cross symbol was perceived ambiguously and posed a danger in case of capture. Nevertheless, their service began.

Women from various social strata participated in the society, from peasant women to the daughters and wives of Russian monarchs. Christian virtue and mercy were the main principles of the society, which existed in Russia until 1917.