Bangladesh forms the larger and eastern part of the Bengal region. According to the ancient Indian texts, "Rāmāyana" and "Mahābhārata", the Vanga Kingdom, one of the namesakes of the Bengal region, was a strong naval power. In the ancient and classical periods of the Indian subcontinent, the territory was home to many principalities, including the Pundra, Gangaridai, Gauda, Samatata, and Harikela. It was also a Mauryan province under the reign of Ashoka. The principalities were notable for their overseas trade, contacts with the Roman world, the export of fine muslin and silk to the Middle East, and spreading of philosophy and art to Southeast Asia. The Gupta Empire, Pala Empire, the Chandra dynasty, and the Sena dynasty were the last pre-Islamic Bengali middle kingdoms. Islam was introduced during the Pala Empire, through trade with the Abbāsid Caliphate, but following the Ghurid conquests led by Bakhtiyar Khalji, the establishment of the Delhi Sultanate and preaching of Shah Jalāl in the north-east, it spread across the entire region. In 1576, the wealthy Bengal Sultanate was absorbed into the Mughal Empire, but its rule was briefly interrupted by the Suri Empire. Mughal Bengal, worth 12% of world GDP (late 17th century), waved the Proto-industrialization, showed signs of a possible Industrial revolution, established relations with the Dutch and English East India Company, and became also the basis of the Anglo-Mughal War. Following the death of Emperor Aurangzeb Alamgir and Governor Shaista Khan in the early 1700s, the region became a semi-independent state under the Nawabs of Bengal. Siraj Ud-Daulah the last of the Nawabs of Bengal was defeated by the British East India Company at the Battle of Plassey in 1757 and the whole region became conquered by the British in 1793.