Imam Janshan

Imam Janshan (born Ali ibn Muhammad, also known as Yusuf ibn Mansur) was the son of Imam Zaman, the last of the Twelve Imams and the founder of the Brethren of Purity. He succeeded his father to become the second leader of that organisation, and was seen by the other members as the thirteenth Imam of Islam.

Like his father, Imam Janshan ran the Brethren of Purity in secret. Publicly, Janshan adopted the persona of Yusuf ibn Mansur, and became a powerful figure in the Sunni Caliphate. He was instrumental in the construction of the House of Wisdom in Baghdad, beneath which he built vaults in which the Brethren of Purity held meetings.

Imam Janshan had seven sons and numerous grandsons. These men gradually replaced all of original Brethren of Purity. The eldest son of Imam Janshan was ordained the fourteenth Imam upon his father's death, and named Imam Khals. Imam Khals succeeded as leader of the Brethren of Purity and curator of the House of Wisdom.