Languages are basically a means of communication, expression of emotion, attitude and mood. But they are also associated with identity in various degrees. Identity is nationalistic, sub-nationalistic (ethnic) and, in some rare cases, also religious. In India, it so happened that Urdu got associated with the Indian-Muslim identity between the late 18and the early 20centuries. Despite the fact that this language is spoken by both Hindus and Muslims and Muslims themselves speak a number of languages, mainly Bengali, Punjabi, Pashto, Sindhi and Gujrati. Moreover, in the villages of UP and Bihar, both Hindus and Muslims actually speak the dialects of Hindi such as Awadhi, Bhojpuri, Braj Bhasha, Maithili etc. And yet, modern Urdu is associated with Islam in India in both India and Pakistan. How did this happen? This is explained in two parts. The first part deals with the movement for the purification of Urdu between 1750 to the early 1900s.The movement for linguistic purification — which I call the ‘Islamisation of Urdu’ for reasons given below — started in the middle of the 18century. The ancestor of Urdu was an Indic-oriented language. By this I mean that it had words of the local languages (bhaka or bhasha) and Sanskrit, and its allusions were to India and the local culture. Even though the script of some writings in this language is Perso-Arabic (Urdu), as opposed to Devanagari used in the Rajput writings, the language is similar. This common language underwent a great change from the 1750s onwards which is the theme of this article.In this purification movement, the Indic element was purged out by Muslim poets who, it appears, wanted a class-identity marker. Among the changes which occurred were: the removal of local (bhaka) and Sanskritic words, the substitution of Iranian and Islamic cultural allusions and metaphors in place of Indian and Hindu ones, and the replacement of the Indian conventions about the expression of love (woman to man) by Persian ones (man to woman or adolescent boy). Among the more than 4,000 words purged out were nain (eye), prem (love), mohan (dear one) etc. They do exist in songs and some other forms of poetry, of course, but they were banished from the ghazal. The grounds given in the writings of the poets who did all this — such as Shah Hatim (1699-1786), Imam Baksh Nasikh (d. 1838), Insha Ullah Khan Insha (1752-1818), etc — are not communal. They said that certain words are obsolete, unfashionable and rough. However, the end result was that words of Indic origin were the ones which were purged. That is one reason why I call this movement ‘Islamisation’. To take one concrete example, Hatim made a small extract of his voluminous poetic work calling it Divan Zada (1756). In the preface of this compilation, he writes in Persian that he “had stopped using the local idiom which was called ‘bhaka’” (bhaka goend mauquf karda). In its place, he tells us, he had started the refined idiom of the gentlemen of Delhi. And what was this? For an answer we have to go to Insha who defined it precisely in his Persian book Darya-e-Latafat (1802). For Insha, this was the language of the Muslim elite of Delhi and Lucknow. Such notions about linguistic excellence were in circulation from the 14century at least, as Amir Khusro’s own notions illustrate. However, during the 1750s the ideas of Sirajuddin Ali Khan Arzu (1687-1756), a Persian poet and linguist, had a stronger impact on Hatim and the other reformers. Arzu corrected an existing dictionary naming it Navadir-ul- Alfaz (1751). In this he indicates at several places that the standard language he had in mind was that of the elite of Delhi. And this idiom was far more Persianised and full of Islamic cultural references than the other styles of the language spoken elsewhere. So it was this Persianised language which became a marker of the educated, mostly Muslim but also Hindu Kaesth, identity during British India.The impact of this movement was that it changed the identity of the common language of north India to two languages: Persianised Urdu and Sanskritised Hindi. The process of Sanskritisation started from 1802 onwards and it was a consequence of political awareness, incipient nationalism and reaction to Muslim cultural dominance. But this dominance had been contributed to; by the same movement of the Islamisation of Urdu so that a Hindu poet had to use Islamic phraseology in order to be appreciated. And yet, ironically and most unjustly, Azad’s book Ab-e-Hayat ignores both Hindu poets as well as women. There is no doubt that this process of Persianisation was a class movement meant to strike out an independent path rather than to write in Persian itself as the Iranians made fun of Indian-Persian. Moreover, from the 1830s onwards, Persian was being phased out from the domains of power. Both the Muslims and Kaesth Munshis were interested in using Persianised Urdu to retain their monopoly over jobs in UP and the Punjab. But the apprenticeship (ustadi-shagirdi) tradition, the poetry recitation sessions (mushairas) which were assemblies of rivals and the cultural capital given to language was such that the allusions, references and the atmosphere, at least in the ghazal, was Persian and Muslim. That is why the movement alienated Hindus and that is why I call it the Islamisation of Urdu. Its greatest harm was that it began the division of Urdu-Hindi into Urdu and Hindi and this was continued by the Sankritisation of Hindi later. And yet, the spoken language of ordinary people remains undivided. It is only by recognising this history and resolving to build upon common themes and continuities of this common language of north Indian cities that we exorcise the ghosts of the past from this subcontinent.(For those who want details please refer to chapter five of my book, entitled From Hindi to Urdu: A Social and Political History (OUP 2011).Published in The Express Tribune, August 21, 2011.