Dinapur Nizamat has a total population of 1,82,429 and ranks 102nd in term of Hindi speakers. Dinapur Nizamat is a city of Patna district. Highest employment in Patna district is in the agricultural sector, small-scale industry and the government. Patna district has 49% Agriculture workers, 46% Government employees and other miscellaneous workers and the remaining 5% are employed as household workers. Patna is a good agricultural district since the River Ganga passes through much of the district along with the rivers Sone & Punpun. In fact, Patna City has the longest river line in the world. This region is also known for the Ganga Dolphins. Dinapur Nizamat which is situated on the outskirt of Patna city is one of the oldest European cantonments in the region. It was the only white cantonment of the East India Company between at one point of time. It was the largest military cantonment in Bengal, with accommodation for two batteries of artillery, a European and a native infantry regiment. The history of Patna goes back to 490 BCE when Ajatashatru, the King of Magadha shifted his capital here from Rajgriha. Gautam Buddha travelled through this region in the last year of his life. During the reign of Emperor Ashoka in the 3rd century BCE, Pataliputra was one of the worlds largest cities, with a population of 150,000–400,000. Pataliputra reached the pinnacle of prosperity as the seat of power of the great Mauryan Emperors: Chandragupta Maurya and Ashoka. Megasthenes, the Greek ambassador to the court of Chandragupta Maurya, wrote detailed accounts of the splendour of "Palibothra" which lay at the confluence of Rivers Ganga and Sone. After Ashoka, the city also became a flourishing Buddhist centre boasting of a number of important monasteries. It remained the capital of the Gupta dynasty (3rd–6th centuries) and the Pala Dynasty (8th-12th centuries). The city was largely in ruins when visited by Xuanzang, and suffered further damage at the hands of Muslim raiders in the 12th century. Later, Sher Shah Suri made Pataliputra his capital and changed the name to modern Patna. One of the nav ratnas from Akbars court, his official historian and author of "Ain-i-Akbari" Abul Fazl refers to Patna as a flourishing centre for paper, stone and glass industries. He also refers to the high quality of the numerous strains of rice grown in Patna, famous as “Patna Rice” across Europe even today. Patna remained the capital of Bihar after India gained independence in 1947 and even as Bihar was partitioned again in the year 2000 with Jharkhand branching out as a separate state. Today, Patna is the 19th largest city in India.