In the Seljuk period, figurative themes of Turco-Mongol character are some what apparent in all the minor arts in both Iran and Iraq. The true Persian miniature, however, which is indisputably the most perfect figurative art on the soil of Islam, did not come into the world until after the conquest of Iran by the Mongols, and more precisely under the rule of the Īl-Khāns (1256). It is modeled upon Chinese painting with its perfect blend of calligraphy and illustration...The link between writing and image remains fundamental to Persian miniatures, which, belongs, as a whole, to the art of books; all the famous miniaturists were calligraphers before becoming painters.
Titus Burckhard in: Art of Islam: Language and Meaning, World Wisdom, Inc, 2009, P.37