Dąbrowski was born in 1836, after the Partitions of Poland, in Żytomierz, in the Volhynian Governorate of the Russian Empire, in what is now Zhytomyr in Ukraine.

[2] In 1845 at age 9, Dąbrowski joined the Imperial Russian Army, enrolling in the officer training corps at the Brest-Litovsk Fortress, where he spent 8 years.

Members included several hundred Russian and Polish officers, cooperating with the revolutionary "Zemlya i Volya" (Land and Liberty) movement.

[8] He became involved in the preparation of the January Uprising, but was arrested on 14 August 1862, and exiled to Siberia for his participation in a plot against the Tsar, Alexander II.

[14] The misidentification with pianist Henri Dombrowski can be seen in many monuments and portrayals of Jarosław Dąbrowski as a result of Petit's actions.

[15] In the Spanish Civil War (1936–1939), the Dabrowski Battalion and various brigade-strength units (known in Polish as the Dąbrowszczacy) – were named in his honour.