[note 1][2][3] The city of Jahangirnagar (now Dhaka) was Bengal Subah's capital in the mid-eighteenth century and Urdu-speaking merchants from North India started pouring in.
Eventually residing in Dhaka, interactions and relationships with their Bengali counterparts led to the birth of a new Bengali-influenced dialect of Urdu.
[5] Their Urdu language also influenced the dialect of the Bengali Muslims in Old Dhaka city which came to be known as the Dhakaiya Kutti[6] and vice versa.
[7] Sobbasi/Khosbasi is not the name of any language but the adjective and identifies some communities as referred by Hakim Habibur Rahman in Dhaka Pachas Baras Pahle.
Habibur Rahman was a prominent Dhakaiya physician and litterateur whose most famous books include Asudegan-e-Dhaka and Dhaka Panchas Baras Pahle.
Often described as a wealthy and closed-off community, speakers of the dialect honour the Dhakaiya Urdu poets of the past in privacy within their mushairas.
Khurshid Alam and Sabina Yasmin sang a song, Matiya Hamar Naam, in this dialect for the Bangladeshi film Jibon Niye Jua which released in 1975 after the Independence of Bangladesh.