When the Britishers were looking to expand from the trading town of Hooghly, they moved downstream to three villages – Kolikata, Sutanuti and Gobindapur. They started a factory at Sutanuti on August 24, 1690, which is widely accepted as the day modern Calcutta was founded.
The site was selected very carefully with protection on west by Hooghly River, a creek in north, and salt lakes in east. The three villages of were part of a khas mahal or imperial jagir or an estate belonging to the Mughal emperor himself, whose jagirdari rights were held by the Sabarna Roy Choudhury family.
The Roy Choudhury family had to transfer their rights in 1698, to East India Company against their wish at the behest of Mughals. This set the growth of Kolakata in motion which later replaced Murshidabad, the capital city of Bengal.
Siraj ud-Daulah, the Nawab of Bengal, was concerned with enhanced fortifications of Kolkata and decided to attack Kolkata. After capturing Kolkata, Siraj ud-Daula named it Alinagar, after his grandfather Alivardi Khan. The name of Kolkata was restored in 1758, after the British regained control.