Ferdowsi or Firdawsi (His complete name, Hakim Abu'l-Qasim Firdawsi Tusi: 935–1020) was a highly revered Persian poet. He was the author of the Shahnama, the national epic of the Greater Iran and Persain-speaking people.
The son of a wealthy land owner (or in Persian Dehqan), Ferdowsi devoted more than 30 years of his life to compose Shahnama. When he was young, he found a “Shahnama” written by Abu-Mansour Almoammari; however, it was not in poetic form. This version of Shahnama along with other versions such as Daqiqi’s version (which he used without any change) made a base for Ferdowsi to write Shahnama.
As confirmed from the beginning of Shahnama and by early accounts such as in books of Nizami of Samarkand, Ferdowsi was a Shia Muslim. This is also apparent from his name. Ferdowsi’s patronymic nickname was Abu'l Qasim, which is a popular name among Shias. On the other hand, Ferdowsi clearly respected the religion of his forbears and, at the same time, nowhere did he show any signs of a deep Islamic faith. Especially when many scholars believe that Shi’ism was a form of Iranian Nationalistic protests against Caliphate’s reign.
Ferdowsi is said to have died around 1020 in poverty at the age of 85.
For a full biography of Ferdowsi see this link: www.iranica.com/newsite/index.isc?Article=http://www.iranica.com/newsite/articles/unicode/v9f5/v9f541a.html