He joined the uprising and initially served in Polish militia. Later he formed and equipped a Jewish cavalry regiment and commanded it in the forces of Tadeusz Kościuszko. His unit took part in the 1794 defence of Praga, in which they suffered heavy casualties.
After the Uprising has been defeated, Joselewicz left for Italy. There he joined the Polish Legions under Henryk Dąbrowski. As a commander of sabre company in Polish cavalry units he fought in various battles of the Napoleonic period. Among them were the battles of Trevia, Novi, Hohenlinden, Austerlitz and Friedland. He was awarded with Virtuti Militari medal for his merits. From Poland. He was killed in the Battle of Kock in 1809.
Polish Army colonel, squadron leader of the 5th Regiment of the Mounted Fusiliers of the Grand Duchy of Warsaw, knight of the crosses of the Legion of Honour and of Virtuti Militari.
BerekJoselewicz (1760-1809) spent some time in Paris, where he witnessed the outbreak of the French Revolution.
After the collapse of the uprising, Joselewicz emigrated from Poland and was amember of the Polish legions in Italy.