Today is Monday; 1st of the Iranian month of Shahrivar 1395 solar hijri, corresponding to 19th of the Islamic month of Zi’l-Qa’dah 1437 lunar hijri; and August 22, 2016, of the Christian Gregorian Calendar.
719 lunar years ago, on this day in 718 AH, the Iranian Muslim mathematician and physicist, Kamal od-Din Hassan Ibn Ali al-Farisi, passed away. Born in Tabriz, he made two major contributions to science, one on optics, the other on number theory. Farisi was a pupil of the great astronomer and mathematician Qutb od-Din ash-Shirazi, who in turn was a pupil of the famous Khwaja Naseer od-Din Tusi. His work on optics was prompted by a question put to him concerning the refraction of light. Shirazi advised him to consult "Kitab al-Manazer” (Book of Optics) of Ibn al-Haytham, and Farisi made such a deep study of this treatise that Shirazi suggested that he write what is essentially a revision of that major work, which came to be called the "Tanqih al-Manazer".  Farisi is known for giving the first mathematically satisfactory explanation of the rainbow, and an explication of the nature of colours. He also made a number of important contributions to number theory. His most impressive work in number theory is on amicable numbers. In "Tadhkirat al-Ahbaab fi Bayan at-Tahabb" (Memorandum for Friends on the proof of Amicability) he introduced a major new approach to a whole area of number theory, introducing ideas concerning factorization and combinatorial methods. In fact Farisi's approach is based on the unique factorization of an integer into powers of prime numbers.
661 lunar years ago, on this day in 776 AH, Mohammad Shah I, the second ruler of the Bahmani Dynasty of the Deccan in southern India, passed away in his capital Golbarga after a reign of 17 years, and was succeeded by his son, Mujahid Shah. Better known as organizer of the Bahmani Empire that was founded by his father, Ala od-Din Hassan Gangu Bahman Shah – a general of Iranian origin who revolted against the excesses of the Turkic ruler of northern subcontinent, Sultan Mohammad Tughlaq – Mohammad Shah I founded many institutions and was a patron of Persian language and literature. The Bahmani Sultanate, which lasted for 180 years, developed a distinct Muslim culture and style of architecture that evolved out of direct contact with Iran and the migration in large numbers of Iranian scholars, poets, architects, traders, statesmen, and soldiers.
490 solar years ago, on this day in 1526 AD, Sultan Qutb od-Din Bahadur Shah, after returning from exile in Delhi, ascended the throne of Gujarat in western India by removing his youngest brother Mahmoud Shah II, who had been installed as king by the nobles on the murder of the eldest brother, Sikandar Shah, within a few months of the death of his father, Muzaffar Shah II. During his 11-year reign he had to face the menace of the Portuguese who raided the seaports of his realm and seized several islands including what would later be known as Bombay (renamed Mumbai today). He made the fatal mistake of seeking assistance from the Portuguese against the expansion of the Mughals of northern India. While on board a Portuguese ship to sign a treaty, he was treacherously killed by the Portuguese admiral and his body dumped into the sea. The Gujarat kingdom that declared itself independent of the Delhi Sultanate in 1407 by Muzaffar Shah I (son of a Rajput convert to Islam) was a Persianate state and promoted Islamic art, culture and architecture for 166 years until its annexation by the Mughal Emperor, Akbar the Great in 1573.
389 solar years ago, on this day in 1627 AD, the last Battle of La Rochelle broke out between the French Catholics and Protestants. This battle started due to provocation by England. The Catholics, under command of Cardinal Richelieu emerged victorious in the battle of La Rochelle in western France.
377 solar years ago, on this day in 1639 AD, Madras (now Chennai), was founded by the British East India Company on a sliver of land bought from local Nayak rulers in the district of Chennaipatanam which was leased from King Abdullah Qutb Shah of the dynasty of Iranian origin of Hyderabad-Deccan. The area was added to the Qutb Shahi dominions by the Iranian statesman and adventurer, Mohammad Sa’eed Ardestani of Isfahan, titled "Mir Jumla”, who later went over to the Mughal court in northern India, was made governor of