Populated area of Mailsi in ancient times was restricted to the banks of the river Sutlej. Areas to the east of riverine tract were inhabited by two ethnic groups namely Arain from Lahore and Khichhis from Bakaner, the earliest settlers of the town. They are still the most dominant segment of the town’s population.

Vehari is a new district. Literally Vehari means low lying riverine settlement. It is situated on the right bank of river Sutlej, in the heart of Nili Bar, the bluish tinge of the water of the Sutlej. The construction of Pakpattan Canal from Sulemanki Head Works on the Sutlej and the launching of Nili Bar colony project in 1925; considerably added to the population of the district. The ancient history of the area is not well recorded except for the fact that this riverine tract formed the state of Fatehpur during the time of the Mughal King, Akbar, the Great. It was ruled by Fateh Khan of Joya family who founded and gave his name to the town of Fatehpur. Fatehpur still exists at a distance of 15 Kilometers to the south of Mailsi. Some remains of archaeological value are found in this town.