Indo-Persian culture refers to a cultural synthesis present in the Indian subcontinent, which forms the basis of Indo-Muslim culture. It is characterised by the absorption or integration of Persian aspects into the various cultures of modern-day republics of Pakistan, India and Bangladesh. The earliest introduction of Persian influence and culture to the subcontinent was by the Zoroastrian Achaemenid kingdom's conquest of India in the 5th Century CE and then almost a millennia and half later by various Muslim Turco-Persian rulers, such as the 11th-century Sultan Mahmud Ghaznavi, rapidly pushed for the heavy Persianization of conquered territories in northwestern India and Pakistan, where Islamic influence was also firmly established. This socio-cultural synthesis arose steadily through the Delhi Sultanate from the 13th to 16th centuries, and the Mughal Empire from then onwards until the 19th century. Various Muslim dynasties of Turkic, local Indian and Afghan origin patronized the Persian language and contributed to the development of a Persian culture in India. The Delhi Sultanate developed their own cultural and political identity which built upon Persian and Indic languages, literature and arts, which formed the basis of an Indo-Muslim civilization. Persian was the official language of most Muslim dynasties in the Indian subcontinent, such as the Delhi Sultanate, the Bengal Sultanate, the Bahmani Sultanate, the Mughal Empire and their successor states, and the Sikh Empire. It was also the dominant cultured language of poetry and literature. Many of the Sultans and nobility in the Sultanate period were Persianised Turks from Central Asia who spoke Turkic languages as their mother tongues. The Mughals were also culturally Persianised Central Asians (of Turko-Mongol origin on their paternal side), but spoke Chagatai Turkic as their first language at the beginning, before eventually adopting Persian. Persian became the preferred language of the Muslim elite of northern India. Muzaffar Alam, a noted scholar of Mughal and Indo-Persian history, suggests that Persian became the official lingua franca of the Mughal Empire under Akbar for various political and social factors due to its non-sectarian and fluid nature. The influence of these languages led to a vernacular called Hindustani that is the direct ancestor language of today's Urdu–Hindi varieties. The Persianisation of the Indian subcontinent resulted in its incorporation into the cosmopolitan Persianate world of Ajam, known today academically as Greater Iran, which historically gave many inhabitants a secular, Persian identity. History With the presence of Muslim culture in the region in