Garseen Detassi was the prominent French orientalist of nineteenth century. He was a good researcher, critic, historiographer and linguistic as well. His history ''Tareekh Adabiyat e Urdu'' is his valuable work which is the important evidence of eighteenth and nineteenth century Urdu literature. This is the first history in which he gave not only the introduction and piece of writings of poets and prose writers but also gave the detailed introduction of their publications. Linguistic and scriptural discussions, presentation of journalism history, hindustani culture with objective point of view, are the salient features of this history. It is also important due to its research and critical point of view. He consulted multiple scripts and pointed out their condition with compact introduction. He also made comparative study of writings. These are the qualities which made this book as the first prominent parameter of writing an authentic critical history. This article is the detailed study of its research and critical approach.