Situated on the Malwa plateau in Madhya Pradesh, the holy city of Ujjain is the 33rd largest Hindi speaking city of India with a total population of 5,10,000. Highest employment in Ujjain District is in Agriculture, in the Machinery, Oils, Chemicals and Fertilizer Industries and in the refinery. Ujjain has 70% Agriculture workers, 27% workers in Industry and other Services and 3% Household workers. River Kshipra provides ample irrigation to this large agricultural belt. Soybean, wheat, jowar and bajra are the main crops being cultivated. The soil of Ujjain is black and stony. Excavations around Ujjain, at Kayatha (around 26 km from Ujjain) and Nagda, have revealed chalcolithic agricultural settlements dating back to around 2000 BCE. The archaeological investigations have indicated the presence of a 45 m wide and 6.6 m deep moat around the city. According to Puranic texts, a branch of the legendary Haihaya dynasty ruled over Ujjain. In the Mauryan period, Ujjain remained the administrative centre of the region and during the reign of Bindusara, Ashoka served as the viceroy of Ujjain. The city was an important literary centre of ancient India called Adyapeetha or a place for the foundation of Sanskrit learning, ethics, knowledge, science and arts. Ujjain has also been called "Swarna Sringa", as the skyline is dotted with the golden towers of the many temples of this city. The poet Kalidasa also refers to Ujjain many times, and it appears that he spent at least a part of his life here. During medieval times, Ujjain, like other parts of north-central India came under the Islamic rule. In 1235 CE, Iltutmish of Delhi Sultanate plundered the city, and destroyed its temples. However, Ujjain continued to be an important city of the region and till as late as the era of the Mughal vassal Jai Singh II (1688-1743), who had constructed the Jantar Mantar in the city, Ujjain was the largest city and capital of the Malwa Subah. During the 18th century, Ujjain briefly became the capital of the Scindia state of the Maratha confederacy, when Ranoji Scindia established his capital here in 1731, his successors moving to Gwalior in the latter half of the 18th century. On 18 July 1801, the Holkars defeated the Scindias at the Battle of Ujjain. On 1 September, Yashwant Rao Holkar entered the city, and demanded a sum of Rupees 15,00,000 from the city. He received only 1/8th of this amount; the rest was pocketed by his officers. Later, a force sent by Daulat Scindia regained control of Ujjain. After both Holkars and Scindias had accepted the British suzerainty, the British colonial administrators decided to develop Indore as an alternative to Ujjain, since the merchants of Ujjain had supported the anti-British uprising.