Umar Khayyam (Omar Khayyam) was born on May 18, 1048 in Nishapur, Iran. He was an outstanding mathematician and astronomer and, wrote several works including Problems of Arithmetic, a book on music
and one on algebra before he was 25 years old.
In 1070 he moved to Samarkand in Uzbekistan which is one of the oldest cities of Central Asia. There Khayyam was supported by Abu Tahir, a prominent jurist of Samarkand, and this allowed him to write his most famous algebra work, Treatise on Demonstration of Problems of Algebra.
Malik Shah the grandson of Toghril Beg, the founder of the Seljuk dynasty ruled the city of Isfahan from 1073 AD. His vizier Nizam-ul-Mulk invited Khayyam to Isfahan, to set up an observatory. Other leading astronomers were also invited to work at the observatory and for 18 years Khayyam led the scientists and produced work of outstanding quality. It was a period of peace during which the political situation allowed Khayyam the opportunity to devote himself entirely to his scholarly work. During this time Khayyam led work on compiling astronomical tables and he also contributed to calendar reform in 1079. Khayyam measured the length of the year as 365.24219858156 days, we know now that the length of the year is changing in the sixth decimal place over a person's lifetime. It is also outstandingly accurate. For comparison the length of the year at the end of the 19th century was 365.242196 days, while today it is 365.242190 days.
Outside the world of mathematics, Khayyam is best known as a result of Edward Fitzgerald's popular translation in 1859 of nearly 600 short four line poems the Rubaiyat. Khayyam's fame as a poet has caused some to forget his scientific achievements which were much more substantial. Versions of the forms and verses used in the Rubaiyat existed in Persian literature before Khayyam, and only about 120 of the verses can be attributed to him with certainty.
Umar Khayyam died on Dec 04, 1131.