Though a lot has been said about the legendary star couple Nargis and Sunil Dutt, Kishwar Desai's biography on the duo has more to offer by giving a vivid picture of their lives, based on diaries and letters of Nargis, Sunil and their daughter Priya Dutt.

Titled, "Darlingji" -- as the couple often used to address each other, the book tracks the larger landscape of Hindi cinema, of a society and a nation in transition.

"I felt compelled to write about the indomitable faith they had in their love despite their social and religious backgrounds, as also the odds they defeated to be with each other. Their story is a classic example of social cohesion, a good idea of what India was meant to be," Desai told.

"The book documents not only the life of India's two best actors but also a nation in transition, India after the Partition, especially the film industry. It was very important to give the reader a sense of the period and one had to be accurate and objective at the same time," she said.

Desai and her NRI husband, Lord Meghnad Desai, had originally planned to write a book on Nargis. In 2005, they approached Sunil Dutt for the material to write the book.

But the actor passed away the same year. After that, the Dutt family collated all photographs and letters and diaries that Dutt had treasured through his life.