[5] Some sources consider Urmia in northwestern Iran to have been his birthplace,[3] while the Iranian historian Abdul-Hadi Hairi consider him to have been born in Russian Armenia.

[3] It was in Alexandropol that Haydar started his education, continuing his studies in higher institutions in Yerevan and then Tbilisi, where he graduated in 1899 with a degree in electrical engineering.

[2] On the very day that the Anglo-Russian Agreement was signed in St. Petersburg in 1907, bisecting Iran into two spheres of influence, Ali Asghar Khan, the powerful Iranian premier, was shot in front of the Majles.

Haydar Khan who by that time became known under the pseudonym "Bombist" for his terrorist activities, was found responsible for the plot and was arrested, but he was soon released at the insistence of his parliamentary Social Democrat comrades.

[2] During this conflict, Haydar Khan first escaped to Caucasia, where he helped in the provision of men and material for the revolutionaries, before returning to fight them.

Once the Shah had been dethroned, he joined the radical Democratic Party and organized the assassination in January 1910 of Ayatollah Mirza Sayyed Abdullah Behbahani, who led the conservative wing of the Constitutionalists.

The 1917 Russian Revolution provided an opportunity for Haydar Khan to return to the Caucasus and participate in the Baku Congress in 1921 as one of the leaders of the Iranian delegation.

Haydar Khan was sent back to Iran by the Bolsheviks to settle the conflict which was raging between the Jangalis and the Communist Party of Persia in Gilan.