Omar Khayyam, Arabic in full Ghiy?th al-D?n Ab? al-Fat? ?Umar ibn Ibr?h?m al-N?s?b?r? al-Khayy?m?, (born May 18, 1048, Neysh?b?r [also
spelled N?sh?p?r], Khor?s?n [now Iran]?died December 4, 1131, Neysh?b?r), Persian mathematician, astronomer, and poet, renowned in his own country and time for his scientific achievements but chiefly known to
English-speaking readers through the translation of a collection of his rob???y?t (“quatrains”) in The Rubaiyat of Omar Khayyam (1859), by the English writer Edward FitzGerald.

His name Khayyam (“Tentmaker”) may have been derived from his father’s trade. He received a good education in th
e sciences and philosophy in his native Neysh?b?r before traveling to Samarkand (now in Uzbekistan), where he completed t
he algebra treatise, Ris?lah fi?l-bar?h?n ?al? mas??il al-jabr wa?l-muq?balah
(“Treatise on Demonstration of Problems of Algebra”), on which his mathematical reputation principally rests. In this treatise he gave a systematic discussion of the
solution of cubic equations by means of intersecting conic sections. Perhaps it was in the context of this work that he discovered how to extend Abu al-Waf?’s results on the extraction of cube and fourth
roots to the extraction of nth roots of numbers for arbitrary whole numbers n.

He made such a name for himself that the Seljuq sultan Malik-Sh?h invited him to E?fah?n to undertake the astronomical observations necessary for the reform of the calendar. (See The Western calendar and calendar
reforms.) To accomplish this an observatory was built there, and a new calendar was produced, known as the Jal?l? calendar. Based on making 8 of every 33 years leap years, it was more accurate than the present Gregorian calendar,
and it was adopted in 1075 by Malik-Sh?h. In E?fah?n he also produced fundamental critiques of Euclid’s theory of parallels as well as his theory of proportion. In connection with the former his ideas eventually made their way to Europe,
where they influenced the English mathematician John Wallis
(1616?1703); in connection with the latter he argued for the important idea of enlarging the notion of number to include ratios of magnitudes (and hence such irrational numbers as Square root of√2 and π).

His years in E?fah?n were very productive ones, but after the death of his patron in 1092 the sultan’
s widow turned against him, and soon thereafter Omar went on a pilgrimage to Mecca. He then returned to Neysh?b?r where he taught and served the court as an astrologer. Philosophy, jurisprudence, history,
mathematics, medicine, and astronomy are among the subjects mastered by this brilliant man.

Omar’s fame in the West rests upon the collection of rob???y?t, or “quatrains,” attributed to him.
(A quatrain is a piece of verse complete in four lines, usually rhyming aaaa or aaba; it is close in style and spirit to the epigram.) Omar’s poems had attracted comparatively little attention until they inspired FitzGerald to write
his celebrated The Rubaiyat of Omar Khayyam, containing such now-famous phrases as “A Jug of Wine, a Loaf of Bread?and Thou,” “Take the Cash, and let the Credit go,” and “The Flower that once has blown forever dies.”
These quatrains have been translated into almost every major language and are largely responsible for colouring European ideas about Persian poetry. Some scholars have doubted that Omar wrote poetry. His contemporaries
took no notice of his verse, and not until two centuries after his death did a few quatrains appear under his name. Even then, the verses were mostly used as quotations against particular views ostensibly held by Omar,
leading some scholars to suspect that they may have been invented and attributed to Omar because of his scholarly reputation.

Each of Omar’s quatrains forms a complete poem in itself. It was FitzGerald who conceived the idea of