 Islam does not recognize any castes, but, when it came to Persia and India, the existing divisions in these regions were adopted among the local Muslim societies.Evidence of social stratification can be found in several later Persian works, such as "Siyasatnama" of Nizam al-Mulk (11th century), "Akhlaq-i Nasiri" of Nasir al-Din al-Tusi (13th century), and "Jam-i-Mufidi" (17th century).The Muslims who came to the subcontinent during the 12th century Muslim conquests on the Indian subcontinent were already divided into social classes such as priests, nobles and others.