He spent his early career in the sixth regiment (fawj-e sheshom) of Azerbaijan, which he led as sarhang during the siege of Herat in 1837–1839.

[2] Due to Aziz Khan's ability to read and write, as well having a good handwriting, he joined the sixth regiment (fawj-e sheshom) of Azerbaijan at Tabriz.

According to the modern historian J. Calmard, Amir Kabir's support was crucial for Aziz Khan's future rise to power due to the latter's Sunni and modest background.

When Aziz Khan returned to the capital of Tehran on 12 March 1851, he was given a friendly reception with Naser al-Din Shah.

[2] While Naser al-Din Shah was travelling to Persian Iraq along with Amir Kabir (from May to October 1851), Aziz Khan served as the commander of the army and the fortress at Tehran.

[3] Later in the same year, Aziz Khan personally arranged the execution of Táhirih, an influential figure in the newly established Bábi Faith.

During the same month, Aziz Khan had an "impressive military parade" arranged for Naser al-Din Shah at Soltaniyeh.

[6] They soon made a deal that Mirza Aqa Khan would secure her sons nomination, while Jeyran in exchange agreed to hide the most harmful charges in list as well give him the names of the conspirators.

[8][2] His dismissal was made official during a court ceremony by Ali Khan Maragha'i,[2] who had supervised the execution of Amir Kabir in 1852.

Following the assignment of the governorship of Azerbaijan to the crown prince Mozaffar ad-Din Mirza in 1860/61, Aziz Khan succeeded him as the minister of war and head of the armed forces, but lost his pishkar office.

[2] Aziz Khan was reinstated as the pishkar of Azerbaijan in 1870/71, but he was by then old and sluggish, unable to handle the courtiers of Mozaffar ad-Din Mirza.

[2] The English orientalist and diplomat Edward Eastwick, who saw Aziz Khan in Tabriz in 1860 September, recounts him as "a large brawny man, with bloodshot eyes, and inflamed features... he had lately walled up fourteen robbers, two of them with their heads downward, and so left them to perish.

"[2] The contemporary Iranian historian and geographer Mirza Ja'far Haqayeqnegar Khormuji (died 1883) commended Aziz Khan for his "sense of justice and chivalrous qualities".