Amoghavarsha I (also known as Amoghavarsha Nrupathunga I ) (r.814–878 CE) was a Rashtrakuta emperor, the greatest ruler of the Rashtrakuta dynasty, and one of the great emperors of India. His reign of 64 years is one of the longest precisely dated monarchical reigns on record. Many Kannada and Sanskrit scholars prospered during his rule, including the great Indian mathematician Mahaviracharya who wrote Ganita-sara-samgraha, Jinasena, Virasena, Shakatayan and Sri Vijaya (a Kannada language theorist). Amoghavarsha I was an accomplished poet and scholar. He wrote (or co-authored) the Kavirajamarga, the earliest extant literary work in Kannada, and Prashnottara Ratnamalika, a religious work in Sanskrit. During his rule he held titles such as Nrupathunga, Atishadhavala, Veeranarayana, Rattamarthanda and Srivallabha. He moved the Rashtrakuta regal capital from Mayurkhandi in the Bidar district to Manyakheta in the Gulbarga district in the modern Karnataka state. He is said to have built the regal city to "match that of Lord Indra". The capital city was planned to include elaborately designed buildings for the royalty using the finest of workmanship. The Arab traveler Sulaiman described Amoghavarsha as one of the four great kings of the world. Sulaiman also wrote that Amoghavarsha respected Muslims and that he allowed the construction of mosques in his cities. For his religious temperament, his interest in the fine arts and literature and his peace-loving nature, historian Panchamukhi has compared him to the emperor Ashoka and given him the honorific "Ashoka of the South". Amoghavarsha seems to have entertained the highest admiration for the language, literature and culture of the Kannada people as testified to in the text Kavirajamarga.