This disrict is named after the city of Ujjain. The early history of Ujjain is lost in the midst of antiquity. As early as the time of the Aryan settlers, Ujjain seems to have acquired importance. By the 6th century B.C. Avanti with its capital at Ujjaini, is mentioned in Buddhist literature as one of the four great powers along with Vatsa, Kosala and Magadha.