Sheikh Bahai, Iran's iconic theologian, astronomer, engineering genius

In the magnificent mausoleum of the eighth Shia Imam, Ali ibn Musa Reza (AS) in the city of Mashhad, nestled between the Goharshad Mosque, Sahn-e Azadi, and the Imam Khomeini Portico, lies the resting place of Sheikh Bahai.

The beautiful marble grave, inscribed with Quranic verses, is one of the main attractions for pilgrims inside the shrine, who recite prayers and pay obeisance to the legendary Iranian polymath.

Baha al-Din Muhammad ibn Husayn al-Amili (1547–1621), also known as Bahaddin Amili or Sheikh Bahai, was an Iranian-Lebanese Islamic scholar, poet, philosopher, architect, mathematician, and astronomer who lived during the late 16th and early 17th centuries in Safavid-ruled Iran.

He was born in Baalbek, Ottoman Syria (present-day Lebanon), and immigrated to Iran with his family during childhood.

Sheikh Bahai was educated by his father, Shaykh Ḥusayn—a theologian—and by renowned scholars in mathematics, astronomy, and medicine.

He served for many years as the shaykh al-Islām (chief judge of the Muslim court of law) of Isfahan during the reign of Shah Abbas I. Sheikh Bahai authored a treatise on Shi’ite jurisprudence and its application in Iran (Jami e Abbasi).

The Iranian polymath was an expert in a broad range of disciplines, including theology, philosophy, law, astronomy, and mathematics. He was also known as a poet, a grammarian, and an architect.

Sheikh Bahai has been regarded as a literary and theological luminary of his era and the mojadded of the 11th-17th centuries.

The Islamic scholar mentored numerous students during his lifetime, including the prominent Muslim philosopher Molla Ṣadra.

Throughout his life, Sheikh Bahai traveled across the Muslim world. However, in his later years, he chose to settle in Iran.

He was given a place of honor at the court of Shah Abbas I in Isfahan. After some time in the public sphere, he withdrew from social life to devote himself to spiritual matters.

Sheikh Bahai’s works

Sheikh Bahai was a prolific author, composing perhaps as many as one hundred works in Arabic and Persian.

He compiled a literary‐religious‐scientific anthology titled Kashkul, which—apart from its literary and scientific significance—is crucial to understanding human nature and thought.

Another notable anthology, Meḵlaṭ, encompasses a diverse range of subjects. He also produced works on tafsir (Quranic commentary), ḥadith (Prophetic traditions), and fiqh (Islamic jurisprudence).

Sheikh Bahai wrote a book of divination (Fal-nama) and numerous other works on the occult sciences.

As a poet, he is best remembered for his two allegorical mathnawis, “Nan o Halwa” and “Shir o Shakar.” He composed poetry on mystical themes, and his verses continue to be cherished by readers.

An erudite grammarian and scholar of the Arabic language, he authored several books on Arabic grammar, including “The Secrets of Eloquence,” “All Eternal Directives Respecting the Science of Arabic Grammar,” and “The Elevated Words.”

His religious writings include “The Forty Hadith Compilation”—an annotated collection of forty traditions attributed to the Prophet Muhammad (PBUH)—and “The Orchards of Veracity in Commentary upon the Sahifa al-Sajjadiyya.”

He also wrote extensively on the science of Hadith-Tradition, a treatise on pilgrimage, a treatise on fasting, a treatise on the law of obligatory prayer, and a treatise on the law of ritual prostration.

As an Islamic jurist, Sheikh Bahai made significant contributions to Islamic law through works such as “The Dawning Place of the Two Suns and the Elixir of Twofold Felicity,” “Issues in Jurisprudence, The Treatise on Establishment of the Doctrines of the Shi'a,” “The Legalistic Aspects and the Doctrinal Fundamentals, Essence of the Foundations of Jurisprudence,” and “Treatise on the Determination of the Qibla.”

Sheikh Bahai – astronomer and mathematician

In 2009, UNESCO inscribed Sheikh Bahai on the list of Iranian dignitaries in recognition of his contributions to astronomy.

He is considered one of the earliest astronomers to propose the possibility of Earth’s motion before Copernican discoveries became widespread.

He authored an astronomical treatise titled “Fi Tasriḥ al-Aflak” (Anatomy of the Celestial Spheres). In the summary of this work, he supports the idea of Earth’s positional rotation, arguing that no conclusive evidence had yet been presented to refute the concept.

Some records indicate that Sheikh Bahai wrote as many as seventeen tracts and books on astronomy and related fields, including glosses and commentaries on earlier astronomical texts.

He also penned “Risalah dar ḥall‐i ishkal‐i ʿuṭarid wa qamar” (Treatise on the Problems of the Moon and Mercury), which sought to resolve inconsistencies in the Ptolemaic system within the framework of Islamic astronomy.

Sheikh Bahai made the practical achievements of seven centuries of Islamic mathematical culture accessible to his region.

His “Khulasat al‐Hisab” (Essentials of Arithmetic) became the most popular textbook across the Islamic world—from Egypt to India—until the 19th century. This book was translated into German by G. H. F. Nesselmann in 1843, with a French translation following in 1854.

Sheikh Bahai’s engineering feats

One of Sheikh Bahai’s most celebrated architectural achievements is the Sheikh Lotfollah Mosque in Isfahan.

Regarded as a masterpiece of Iranian architecture, the mosque is praised for its exquisite tile work and harmonious proportions.

Its unique features—including a single-shell dome and the absence of minarets—set it apart from other mosques of its era. The interior, adorned with intricate calligraphy and mosaics, reflects Sheikh Bahai’s profound understanding of art and spirituality.

Historical records attribute the architectural planning of Isfahan during the Safavid era to Sheikh Bahai. He is credited with designing Isfahan's Imam Square and Hessar Najaf. He also constructed a sundial to the west of the Imam Mosque.

The Persian engineer devised a system for distributing water from the Zayandeh-Rud River via a complex network of irrigation canals, based on a distribution chart known as Bahai’s scroll.

Utilizing a series of qanats (underground water channels), he engineered a method to efficiently transport water throughout Isfahan, ensuring a reliable supply for its residents. This system showcased not only his engineering brilliance but also his commitment to public welfare.

He also designed the Zarrin Kamar Canal in Isfahan, considered one of Iran's greatest canals.

According to popular legend, Sheikh Bahai engineered a heating system for a public bath in Isfahan that astonishingly warmed water using a single candle.

Beyond his scholarly achievements, the Iranian genius was known for his charitable endeavors. He converted his home into a refuge for orphans, widows, and the destitute.