The concept of a Malay race was originally proposed by the German scientist Johann Friedrich Blumenbach (1752-1840), and classified as the brown race. Since Blumenbach, many anthropologists have rejected his theory of five races, citing the enormous complexity of classifying races. The concept of a 'Malay race' differs with that of the ethnic Malays centered around Malaysian Malay Peninsula and parts of the Indonesian island of Sumatra. The term Malay race was commonly used in the late 19th century and early 20th century to describe the Austronesian peoples.