The book titled 'A Forgotten Empire: Vijayanagar; A Contribution to the History of Southern India' was written by Robert Sewell. Published in 1900, this book is a significant historical account of the Vijayanagar Empire, relying on various sources including foreign travellers' accounts and local records. Sewell, an officer in the Indian Civil Service, played a key role in documenting the history and archaeology of Southern India, particularly the ruins of Hampi, the capital of the Vijayanagar Empire.