Ferdowsi started writing the Shahnameh in 977 AD and completed it on 8 March 1010. The Shahnameh is a monument of poetry and historiography, being mainly the poetical recast of what Ferdowsi, his contemporaries, and his predecessors regarded as the account of Iran's ancient history. Many such accounts already existed in prose, an example being the Abu-Mansuri Shahnameh. A small portion of Ferdowsi's work, in passages scattered throughout the Shahnameh, is entirely of his own conception. The Shahnameh is an epic poem of over 50,000 couplets, written in early Modern Persian. It is based mainly on a prose work of the same name compiled in Ferdowsi's earlier life in his native Tus.