The History of East Asia generally encompasses the histories of China, Japan, Korea, Mongolia, and Taiwan from prehistoric times to the present. East Asia is not a uniform term and each of its countries has a different national history, but East Asian Studies scholars maintain that the region is also characterized by a distinct pattern of historical development. This is evident in the interrelationship among traditional East Asian civilizations, which not only involve the sum total of historical patterns but also a specific set of patterns that has affected all or most of traditional East Asia in successive layers. Background The study of East Asian history as an area study is a part of the rise of East Asian studies as an academic field in the Western World. The teaching and studying of East Asian history began in the West during the late 19th century. In the United States, Asian Americans around the time of the Vietnam War believed that most history courses were Eurocentric and advocated for an Asian-based curriculum. At the present time, East Asian History remains a major field within Asian Studies. Nationalist historians in the region tend to stress the uniqueness of their respective country's tradition, culture, and history because it helps them legitimize their claim over territories and minimize internal disputes. There is also the case of individual authors influenced by different concepts of society and development, which lead to conflicting accounts. These, among other factors, led some scholars to stress the need for broader regional and historical frameworks. There have been issues with defining exact parameters for what East Asian history which as an academic study has focused on East Asia's interactions with other regions of the world. It has been argued that East Asia and Southeast Asia form a single ethno-cultural area, sharing common roots and history with each other, while being distinct from other world regions. These regions, or the civilizations of China, Japan, and Korea, were under the rule of many dynasties or government systems and their boundaries changed due to inter dynasty wars on a same region or wars between regions. In prehistory, Homo Erectus lived in East and Southeast Asia from 1.8 million to 40,000 years ago. Many belief systems or religions which have evolved and spread in East Asia include Confucianism, Buddhism, and Taoism. China was under the rule of Xia (historicity disputed), Shang and Zhou dynasties followed