bu ʾl-Qasim Ferdowsi Tusi (c. 940–1020), or Ferdowsi was a Persian poet and the author of Shahnameh ("Book of Kings"), which is the world's longest epic poem created by a single poet, and the national epic of Greater Iran. Ferdowsi is celebrated as the most influential figure in Persian literature and one of the greatest in the history of literature. He was called "The Lord of the Word" and "The Savior of Persian Language".

Statue of Ferdowsi in Ferdowsi Square in Tehran, by Sadighi
Ferdowsi belonged to the class of dehqans. These were landowning Iranian aristocrats who had flourished under the Sassanid dynasty (the last pre-Islamic dynasty to rule Iran) and whose power, though diminished, had survived into the Islamic era which followed the Arab conquests of the 7th century. The dehqans were intensely patriotic (so much so that dehqan is sometimes used as a synonym for "Iranian" in the Shahnameh and saw it as their task to preserve the cultural traditions of Iran, including the legendary tales about its kings.
The Muslim conquests of the 7th century had been a watershed in Iranian history, bringing the new religion of Islam, submitting Iranians to the rule of the Arab caliphate and promoting Arabic culture and language at the expense of Persian. By the late 9th century, the power of the caliphate had weakened and local Iranian dynasties emerged.
Ferdowsi grew up in Tus, a city under the control of one of these dynasties, the Samanids whose bureaucracy used the New Persian language rather than Arabic and the Samanid elite had a great interest in pre-Islamic Iran and its traditions and commissioned translations of Pahlavi (Middle Persian) texts into New Persian. Abu Mansur Muhammad, a dehqan and governor of Tus, had ordered his minister Abu Mansur Mamari to invite several local scholars to compile a prose Shahnameh ("Book of Kings"), which was completed in 1010.
According to legend, Sultan Mahmud of Ghazni offered Ferdowsi a gold piece for every couplet of the Shahnameh he wrote. The poet agreed to receive the money as a lump sum when he had completed the epic. He planned to use it to rebuild the dykes in his native Tus. After thirty years of work, Ferdowsi finished his masterpiece. The sultan prepared to give him 60,000 gold pieces, one for every couplet, as agreed. However, the courtier Mahmud had entrusted with the money despised Ferdowsi, regarding him as a heretic, and he replaced the gold coins with silver. Ferdowsi was in the bath house when he received the reward. Finding it was silver not gold, he gave the money away to the bathkeeper, a refreshment seller and the slave who had carried the coins. When the courtier told the sultan about Ferdowsi's behaviour, he was furious and threatened to execute him. Ferdowsi fled Khorasan, having first written a satire on Mahmud, and spent most of the remainder of his life in exile. Mahmud eventually learned the truth about the courtier's deception and had him either banished or executed. By this time, the aged Ferdowsi had returned to Tus. The sultan sent him a new gift of 60,000 gold pieces, but just as the caravan bearing the money entered the gates of Tus, a funeral procession exited the gates on the opposite side: the poet had died from a heart attack.

Ferdowsi's Shahnameh is the most popular and influential national epic in Iran and other Persian-speaking nations. The Shahnameh is the only surviving work by Ferdowsi regarded as indisputably genuine. He may have written poems earlier in his life but they no longer exist. A narrative poem, Yūsof o Zolaykā (Joseph and Zuleika), was once attributed to him, but scholarly consensus now rejects the idea it is his. There has also been speculation about the satire Ferdowsi allegedly wrote about Mahmud of Ghazni after the sultan failed to reward him sufficiently. Nezami Aruzi, Ferdowsi's early biographer, claimed that all but six lines had been destroyed by a well-wisher who had paid Ferdowsi a thousand dirhams for the poem. Introductions to some manuscripts of the Shahnameh include verses purporting to be the satire. Some scholars have viewed them as fabricated; others are more inclined to believe in their authenticity.

Homage: in the book "Avicenna" by Gilbert Sinoué, Ferdowsi appears a few times as a secondary character.