Haydar Khan Amo-oghli, known as "the greatest leftist thinker and theorist of Qajar Iran", was one of the most influential figures of the Constitutional Revolution and later of the Jungle Movement. Amo-oghli, became acquainted with socialist ideas while studying at the Tbilisi Polytechnic University and became a member of the Russian Social Democratic Workers' Party. Amo-oghli fled to the Caucasus after the defeat of the Russian Revolution of 1905 and founded the Hemmat Party in Baku with Nariman Narimanov. After a while, Haydar Khan returned to Iran and the Hemmat Party became the Social Democratic Party. After that, Haydar Khan's terrorist activities began. In 1907, Amin al-Sultan was assassinated by Abbas Agha Tabrizi, a supporter of Haydar Khan. After the bombardment of the Majlis, Haydar Khan went to Baku, where he sent volunteers to fight Mohammad Ali Shah and help the resistance fighters of Tabriz, and he himself came to Tabriz. During the battles of Tabriz, he was involved in killing Shojae Nezam Marandi with a bomb.