Hasan Sabbah is the founder of Nizari Ismaili, known as the “Hashshashin.” The possibly autobiographical information found in Sargozasht-i Seyyednā is the main source for Hasan’s background and early life. According to this, Hasan-i Sabbah was born in the city of Qom, Seljuk Empire, in the 1050s to a Shia family. His father had left the Sawād of Kufa (located in modern Iraq) to settle in the town of Qom, one of the first centers of Arab settlement in Persia and a stronghold of Shia. Early in his life, his family moved to Rayy. Rayy was a city that had a history of radical Islamic thought since the 9th century. Sabbah gained a lot of knowledge. He wanted to become a wise man, so he went to Rey. In Rey, he gave up being a Shia and adopted Ismailism. He went to Cairo to learn more about Ismailism. He was welcomed by Grand Dai Ebu Davud and became the Dai of Khorasan. He manipulated many people with this mission and gained warriors. With these warriors and people who supported him, he gained more supporters. The Sultan of the Seljuk Empire gave the order to capture Sabbah, so Sabbah conquered the unprotected Alamut castle and founded the “Hashshashin.”
He was a great assassin but also had unique knowledge of maths and psychology. He built fake heavens to manipulate his men. His assassin teams were really effective because they feared nothing, so they undertook the most suicidal missions. Not only his men, but he was also the messenger head of the Seljuk Empire, the empire that wanted to kill him.
His men were ignorant because they were not getting an education; Hasan Sabbah knew that if they got an education, they would not believe in him. He even gave drugs to his men, building fake heavens with beautiful girls, fruits, homes, and wines. His men went there once, lived in a fake paradise for weeks, and then were expelled from heaven. They were expelled because Sabbah told them that if they wanted to go to heaven again, they had to do missions. So these fake heavens were rewards.
However, even after the death of Hasan Sabbah and the fall of the Alamut castle, his assassins continued their assassinations as mercenaries, but they messed with the wrong nation, the Mongols. After their attempts to kill the Khan of the Mongol Empire, Hulagu Khan destroyed and burned the entire Alamut castle.
Some of his men went to Europe and disappeared slowly.