Old Hindi
Old Hindi, also known as Khariboli, was the earliest stage of the Hindustani language, and so the ancestor of Modern Standard Hindi and Standard Urdu. Also known as Delhavi, it was spoken by the people of the region around Delhi, in roughly the 12th–14th centuries during the Delhi Sultanate. It was an Apabhramsha which developed from Shauraseni Prakrit.
During the Muslim rule in India, the language began acquiring loanwords from Persian language, which led to the development of Hindustani. It is attested in only a handful of works of literature, including some works by the Indo-Persian Muslim poet Amir Khusrau, verses by the Vaishnava Hindu poet Namdev, and some verses by the Sufi Muslim Baba Farid in the Adi Granth. The works of Bhakti Hindu poet Kabir also may be included, as he used a Khariboli-like dialect. Hindi languages were originally written in different variants of Nagari, and later in the Arabic script in Nastaliq calligraphy.
Some scholars include Apabhraṃśa poetry as early as 769 AD within Old Hindi, but this is not generally accepted.
With loanwords from Persian added to Old Hindi's Prakritic base, the language evolved into Hindustani, which further developed into the present-day standardised varieties of Hindi and Urdu.