During the Sukhothai Kingdom, Most literary works were written in simple prose with certain alliteration schemes. Major works include King Ram Khamhaeng Inscription describing life at the time, which is considered the first literary work in Thai script, but some historians questioned its authenticity. ''Trai Phum Phra Ruang'', written in 1345 by King Maha Thammaracha I, expounds Buddhist philosophy based on a profound and extensive study with reference to over 30 sacred texts and could be considered the nation's first piece of research dissertation.