In the Philippines, the Laguna Copperplate Inscription dating from 900 CE relates a granted debt from a "Maginoo" caste nobleman named "Namwaran" who lived in the historic Tondo which is now part of Manila area. This document mentions a leader of Medang in Java. The Khmer Empire effectively dominated all Mainland Southeast Asia from the early 9th until the 15th century, during which time they developed a sophisticated monumental architecture of most exquisite expression and mastery of composition at Angkor. The distinct culture of the kingdom of Dvaravati first appeares in records around the 6th century. By the 10th century, Dvaravati had come under the influence of the Khmer Empire and by the 12th century Thai tribes had conquered the Chao Phraya River valley of modern-day central Thailand and established the local Sukhothai Kingdom in the 13th century and the Ayutthaya Kingdom in the 14th century. According to the Nagarakertagama, around the 13th century, Majapahit's vassal states spread throughout much of today's Indonesia, making it the largest empire ever to exist in Southeast Asia. The empire declined in the 15th century after the rise of Islamic states in coastal Java, Malay peninsula and Sumatra. By the eight century, less than 200 years after the establishment of Islam in Arabia, the first traders and merchants who adhered to Mohammad's prophecies reportedly appeared in Maritime Southeast Asia. Certain is also, that Islam did not play a notable role anywhere in the archipelago or Indochina before the 13th century. As it happened, widespread and gradual replacement of Hinduism by Theravada Buddhism reflected a popular desire for a more personal, introvert spirituality acquired through individual ritual activities and effort. In addressing the issue of how Islam was introduced into Southeast Asia, most historians have elaborated various scenarios along an Arabia to India and India to Southeast Asia sequence. Opinions vary on the identity and method of the agent. Either Arabian traders and scholars, who did not live or settle in India arrived directly in island Southeast Asia, or Arab traders, that had been settling in coastal India and Sri Lanka for generations. Muslim traders from India (Gujarat), converts of South Asian descend and ethnicity are variously considered as to have played a major role. A number of sources propose the South China Sea as another "route" of Islam introduction. Arguments for this hypothesis include:  In a 2013 EU publication of the "European Commission Forum" an inclusive attitude is being maintained: "Islam spread in Southeast Asia via Muslims of diverse ethnic and cultural origins, from Middle Easterners, Arabs and Persians, to Indians and even Chinese, all of whom followed the great commercial routes of the epoch."