Baha al-Din al-Amili (Arabic: بهاء الدين العاملي; Persian: بهاءالدین عاملی: 18 February 1547 – 1 September 1621), commonly known as Sheikh Bahāʾī, was a Twelver Shia Muslim scholar and polymath in Safavid Iran, who composed various works in Arabic and Persian. Closely tied to the court of Shah Abbas the Great, he became known for his role in the intellectual sphere of Isfahan and is seen as a leading figure in his field, with seventy-seven scholars counted among his students. An ethnic Arab, he was originally from Jabal Amil (present-day south Lebanon) in Ottoman Syria. During his childhood, his family moved to Iran, where his father Husayn ibn Abd al-Samad became the shaykh al-Islam in Herat under Tahmasp I.
He stands out as one of the most influential Arab figures, and figures generally, in shaping the scientific, cultural, urban, and intellectual identity of Safavid Iran. He was the principal planner and architectural mind behind the transformation of Safavid Isfahan, credited with devising the overall spatial logic and ceremonial symbolism of the imperial capital. Sheikh Bahāʾī conceived the urban vision behind Naqsh-e Jahan Square and was instrumental in initiating the planning of the Shah Mosque, Sheikh Lotfollah Mosque, and Ali Qapu Palace. His designs also structured the layout of the Imperial Bazaar and he is also associated with hydraulic innovations and water management projects, though attributions such as the Zarrīn Kamar canal remain speculative. He served as a leading religious scholar in the Imam Reza Shrine, taught Islamic sciences, and contributed to the administration of its religious affairs. He is buried in the shrine.
As chief advisor to Abbas the Great, Sheikh Bahāʾī played a central role in defining the symbolic and geometric principles of Safavid civic and religious architecture. His commanding intellectual leadership and cohesive vision, executed through close collaboration with master builders and artisans, were instrumental in forging the Safavid architectural identity. A prolific author in both Arabic and Persian, Sheikh Bahaʾī composed over one hundred treatises spanning jurisprudence, logic, astronomy, mathematics, and theology—primarily in his mother tongue, Arabic. His contributions also extended to literature and poetry, including didactic and mystical verse in Persian. In his Persian work Tashrīḥ al-Aflāk, he was among the earliest Muslim thinkers to propose the possibility of the Earth’s motion, anticipating the later diffusion of Copernican ideas in the Islamic world.
Sheikh Baha' al-Din (also spelled Baha'uddin) Muhammad ibn Husayn al-'Amili was born near Baalbek, in Ottoman Syria (present-day Lebanon) in 1547. His family had moved there from a small village near Jezzine. After the execution of al-Shahid al-Tani in 1558, his father's mentor, he and his family moved to the neighboring Safavid Empire; first to Isfahan, and from there to Qazvin, the then Iranian royal capital. At the time, the Safavid realm was ruled by king Tahmasp I (r. 1524-1576). Tahmasp I appointed Sheikh Bahāʾī's father to serve as Shaykh al-Islām in several important Safavid cities in order to propagate Twelver Shi'ism amongst the population.Sheikh Bahāʾī completed his studies in Isfahan. Having intended to travel to Mecca in 1570, he visited many Islamic countries including Iraq, Syria and Egypt and after spending four years there, he returned to Iran.
Exact dates of birth and death
The exact dates of his birth and death are different on his grave stone and on the ceramic of the walls of the room where he is buried in.
On the ceramics of the wall: 27 February 1547
On the grave stone: March 1546
On the ceramics of the wall: 30 August 1621
On the grave stone: August 1622
The dates on the wall contain day, month and year, while the dates on the grave stone only contain month and year. The ceramics of the wall are made in 1945. It seems that at that time a research is performed about the exact dates, and, therefore, the information about the day is added to the dates.
According to Baháʼí Faith scholar ‘Abdu’l-Hamíd Ishráq-Khávari, Sheikh Baha' al-Din adopted the pen name (takhallus) 'Baha' after being inspired by words of Shi'a Imam Muhammad al-Baqir (the fifth Imam) and Imam Ja'far al-Sadiq (the sixth Imam), who had stated that the Greatest Name of God was included in either Du'ay-i-Sahar or Du'ay-i-Umm-i-Davud. In the first verse of the Du'ay-i-Sahar, a dawn prayer for the Ramadan, the name "Bahá" appears four times: "Allahumma inni as 'aluka min Bahá' ika bi Abháh va kulla Bahá' ika Bahí".
His interest in the sciences is also apparent by some of his works and treaties, although many of his astronomical treatises are yet to be studied. He probably have written 17 tracts and books on astronomy and related subjects. The following are some his works in astronomy:
Risālah dar ḥall-i ishkāl-i ʿuṭārid wa qamar (Treatise on the problems of the Moon and Mercury), on attempting to solve inconsistencies of the Ptolemaic system within the context of Islamic astronomy.
Tashrīḥ al-aflāk (Anatomy of the celestial spheres), a summary of theoretical astronomy where he affirms the view that supports the positional rotation of the Earth. He was one of Islamic astronomers to advocate the feasibility of the Earth's rotation in the 16th century, independent of Western influences.
Kholasat al-Hesab (The summa of arithmetic) was translated into German by G. H. F. Nesselmann and was published as early as 1843.
Sheikh Baha' al-Din was known for his proficiency in mathematics, architecture and geometry. A number of architectural and engineering designs are attributed to him, but none can be substantiated with sources. He is credited with designing the canal network of the Zayanderud river and a heating system for an Isfahan public bath that used a single candle. Some of his designs may have included the Naqsh-e Jahan Square and Charbagh Avenue in Isfahan.
In the Twelver tradition, Sheikh Bahai is regarded as a leading scholar of his age and a mujaddid of the seventeenth century. His erudition won him the admiration of Shah Abbas, and he was appointed the Sheikh ul-Islam of Isfahan after the death of the previous incumbent. He composed works on tafsir, hadith, grammar and fiqh (jurisprudence).