In the Delhi region of India the native language was Khariboli, whose earliest form is known as Old Hindi. It belongs to the Western Hindi group of the Central Indo-Aryan languages. The contact of the Hindu and Muslim cultures during the period of Islamic administrative rule in India led to the development of Hindustani as a product of a composite Ganga-Jamuni tehzeeb. In cities such as Delhi, the Indian language Old Hindi began to acquire many Persian loanwords and continued to be called "Hindi" and later, also "Hindustani". In southern India (especially in Golkonda and Bijapur), a form of the language flourished in medieval India and is known as Dakhini, which contains loanwords from Telugu and Marathi. An early literary tradition of Hindavi was founded by Amir Khusrau in the late 13th century. From the 13th century until the end of the 18th century the language now known as Urdu was called "Hindi", "Hindavi", "Hindustani", "Dehlavi", "Lahori," and "Lashkari". By the end of the reign of Aurangzeb in the early 18th century, the common language around Delhi began to be referred to as "Zaban-e-Urdu", a name derived from the Turkic word "ordu" (army) or "orda" and is said to have arisen as the "language of the camp", or ""Zaban-i-Ordu"" or natively ""Lashkari Zaban"". The Turko-Afghan Delhi Sultanate established Persian as its official language in India, a policy continued by the Mughal Empire, which extended over most of northern South Asia from the 16th to 18th centuries and cemented Persian influence on Hindustani. The name "Urdu" was first introduced by the poet Ghulam Hamadani Mushafi around 1780. As a literary language, Urdu took shape in courtly, elite settings. While Urdu retained the grammar and core Indo-Aryan vocabulary of the local Indian dialect Khariboli, it adopted the Nastaleeq writing system – which was developed as a style of Persian calligraphy.