New Delhi: Romas left India a long back ago but when? Here, the confusion starts. Whether they left India in waves or was it a one-time movement? Many theories have been proposed to solve this puzzle.

A 62-year professor, Marcel Courthiade from the National Institute of Oriental Languages and Cultures, Universite Paris-Sorbonne, France gave one such theory.

"It was one big exodus, which took place in the 11th century when Mahmud Ghazni invaded Kannauj," the professor opined, speaking at the recently concluded International Roma Conferecne in New Delhi.

India's External Affairs Minister, Sushma Swaraj had also referred to Courthiade' theory, but also had later mentioned the wave theory of exodus during subsequent time periods as well.

Speaking about the language of the Romas, the eminent professor said, "if Romas left India in phases then there should be differences in the language, they speak." But, the case is not so.

The professor is an Albanian born scholar and actvist, who has based his hypothesis on a book written by Abu Naser al-Utbi, the chronicler of Mahmud Ghazni. The book titled 'Kitab-i-Yamini' chronicles the invasion of India by the Afghan invader, including the raid of Kannauj in 1026 AD, and mentions how an entire population of around 53,000 people that included rich, poor, artisans, craftsmen, etc. was taken to Afghanistan as prisoners.

The professor said that he was planning to hold a festival in Kannauj to mark 1,000 years of the deportation."