The area’s early history featured a succession of Indian empires, internal squabbling, and a tussle between Hinduism and Buddhism for dominance. Ancient Bengal was the site of several major Janapadas (kingdoms), while the earliest cities date back to the Vedic period. The region was part of several ancient pan−Indian empires, including the Mauryans and Guptas. It was also a bastion of regional kingdoms. The citadel of Gauda served as the capital of the Gauda Kingdom, the Buddhist Pala Empire (8th–11th century) and Hindu Sena Empire (11th–12th century). Islam was introduced through trade with the Abbasid Caliphate,[12] but following the early conquest of Muhammad bin Bakhtiyar Khalji and the establishment of the Delhi Sultanate, it fully spread across the entire Bengal region. Later, occasional Muslim raiders reinforced the process of conversion by building mosques, madrasas, and khanqahs. During the Islamic Bengal Sultanate, founded in 1352, Bengal was major trading nation in the world and was often referred by the Europeans as the richest country to trade with.[13] Later, it was absorbed into the Mughal Empire in 1576.[14] Simultaneously, some parts of the region were also ruled by several Hindu states, and Baro-Bhuyan landlords, and part of it was briefly overran by the Suri Empire. The Mughal Bengal was heralded as the Paradise of the Nations,[15] since it was the empire’s most economically developed province, and became a leading exporter in the world,[16][17][18] a center of worldwide industries such as cotton textiles, silk,[19] shipbuilding.[20] Its citizens’ living standards were among the world’s most superior.[21][22] Bengal accounted for 40% of Dutch imports from Asia, for example, including more than 50% of textiles and around 80% of silks.[16] Bengal’s economy have waved the period of proto-industrialization.