Khmer inscriptions are a corpus of post-5th century historical texts engraved on materials such as stone and metal ware found in a wide range of mainland Southeast Asia (Cambodia, Vietnam, Thailand and Laos) and relating to the Khmer civilization. The study of Khmer inscriptions is known as Khmer epigraphy. Khmer inscriptions are the only local written sources for the study of ancient Khmer civilization. Beyond their archeological significance, Khmer inscriptions have become a marker of national identity.