Abbas Ali died some three to six months after Reza's birth. Noush Afarin did not had a good relationship with Abbas Ali's other wife and children and shortly after Ali's death, at the urging of her youngest brother, decided to leave Alasht and settle in Tehran. At about the age of fifteen, Reza joined the Cossack Brigade in 1893-94. And about 1903 Reza Khan married Tajmah, a girl from Hamadan, from whom a daughter, Fatemeh, later known as Hamdam al Saltaneh, was born. He divorced Tajmah soon after the birth of Fatemeh. In 1911, serving under the overall command of Abol Hossein Mirza Farmanfarmaian or called Farmanfarma (The prime minister of the time) Reza Khan took part in battles against Salar al-Doleh who was attempting to topple the Government in Tehran and reinstate his brother Mohammad Ali on the throne. Reza gave a good account of himself in that campaign and was promoted to First Lieutenant. His proficiency in handling machine guns elevated him to the rank equivalent to Captain in 1912.
