Like many Poles who disliked quelling an independence movement, he then deserted the French side, and he himself joined the buccaneer organization Brethren of the Coast.
Around 1805–1806 he joined a group of mercenaries freedom fighters recruited by Francisco de Miranda in a failed attempt to liberate Venezuela from Spanish rule.
Following the establishment of Gran Colombia, he lived in Bogotá for at least two years, but political intrigues resulted in his decision to leave South America.
He visited the United States and then traveled to the Middle East, where he worked for Muhammad Ali of Egypt and taught mathematics and English.
[4][3] Encyclopædia Iranica states that at an unspecified time he moved to Iran on the request of then-crown prince Abbas Mirza, and entered Iranian service.
[4] He quickly became on good terms with both the incumbent king Fath Ali Shah Qajar (r. 1797-1834), as well as the crown prince himself.
[4] After his death, a friend of Borowski in the Iranian army, an Italian named Barthelemy Semino, married his widow (an Armenian woman from New Julfa), and he reportedly took care of his children as well.
[1] Alma Mater, however, mentions only Antoni Radziwiłł-Borowski, who also became a general in the Iranian service, and took part in Siege of Herat (1856).