He was born Muhammad ibn Hussain al-Harithi Amili Bahai in 953 AH in Jabal Amil in southern Lebanon. After acquiring early education in his hometown from his father Shaikh Hasan, a noted scholar himself, he moved on to Iran, where he studied under several notable scholars of the time. He authored many groundbreaking works in Shia jurisprudence, including Urwat al-Wuthqa, Habl al-Mateen, and Jaama-e-Abbasi, as well as the first Persian-language jurisprudence manual aimed at the layman. He also trained several great scholars, including Mulla Sadra and Mulla Faiz Kashani. Upon the demise of Muqaddas Ardabili in 993 AH, he was recognized as the Marja Taqleed (supreme religious authority) of the Shia world.
Iran under the Safavid dynasty had a system of clerical guardianship, where a jurist was given supreme authority over the law. This post had first been occupied by the esteemed Muhaqqiq al-Karki. He was followed by Shaikh Ali Minshar, who was Shaikh Bahai's father-in-law. Upon his death, Shaikh Bahai became the Shaikh al-Islam of Iran.
In addition to acquiring religious knowledge, Shaikh Bahai was also a noted architect, mathematician, geographer, astronomer, and poet. He traveled around the world as far east as Ceylon, as far west as Egypt, and as far north as Azerbaijan, learning new arts and sciences. He penned several books on mathematics, architecture, and astronomy, as well as several famous works of Persian poetry. Not since the time of Shaikh Naseeruddin Tusi had the Shia world seen a religious leader who was so well-rounded in so many other fields as well.
In addition to his religious and political contributions in Iran, he also left behind several architectural marvels. Much of Isfehan's landmarks today were designed by him. The most famous of these was a bath called Hammam-e-Bahai (the bath of Bahai). Regardless of the time of the year, the water in the bath was always lukewarm. In their curiosity to find out how it worked, the British destroyed the bath several centuries later. To their surprise, they discovered only a small candle burning below the water reservoir, which had somehow managed to keep the water temperature steady for over 250 years! He also designed the famous Chehel Sotun (the mosque with forty pillars), as well as the famous bridges of Isfehan. Shah Abbas had extended his reign over parts of Iraq, and Shaikh Bahai also began construction on the mausoleum of Imam Ali (peace be upon him) in Najaf.
This polymathic leader and guardian of the Shia world departed from this world in 1031 AH. He was buried in the shrine of Imam Ridha (peace be upon him) in Mash'had.
EDITOR'S NOTE: These articles are adaptations of lectures delivered by Maulana Sadiq Hasan in Karachi, Pakistan, during the 1980s on the lives of the great scholars of Islam. The Urdu lectures can be accessed at Hussainiat.com. For previous articles in this series, please look under the History section.