Zhou rulers. The Classic of Poetry, Zuo Zhuan, and Guoyu classics of the Spring and Autumn period (771–476 BCE) also referred to the sea, but by the name Nan Hai () in reference to the State of Chu's expeditions there. Nan Hai, the South Sea, was one of the Four Seas of Chinese literature. There are three other seas, one for each of the four cardinal directions. During the Eastern Han dynasty (23–220 CE), China's rulers called the sea Zhang Hai (). Fei Hai () became popular during the Southern and Northern Dynasties period. Usage of the current Chinese name, Nan Hai (South Sea), gradually became widespread during the Qing Dynasty. In Southeast Asia it was once called the Champa Sea or Sea of Cham, after the maritime kingdom of Champa (nowadays Central Vietnam), which flourished there before the sixteenth century. The majority of the sea came under Japanese naval control during World War II following the military acquisition of many surrounding South East Asian territories in 1941. Japan calls the sea "South China Sea". This was written until 2004, when the Japanese Foreign Ministry and other departments switched the spelling to , which has become the standard usage in Japan. "West Philippine Sea" is the official designation by the Philippine government of eastern parts of South China Sea that are included in the Philippines' exclusive economic zone. The term is also sometimes incorrectly used to refer to South China Sea as a whole. In China, it is called the South Sea, (), and in Vietnam the East Sea, . In Malaysia, Indonesia and the Philippines, it was long called the South China Sea (, ), with the part within Philippine territorial waters often called the "Luzon Sea", , by the Philippines. However, following an escalation of the Spratly Islands dispute in 2011, various Philippine government agencies started using the name West Philippine Sea. A Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) spokesperson said that the sea to the east of the Philippines will continue to be called the Philippine Sea. In September 2012, Philippine President Benigno Aquino III signed Administrative Order No. 29, mandating that all government agencies use the name West Philippine Sea to refer to the parts of South China Sea within the Philippines' exclusive economic zone, including the Luzon Sea as well as the waters around, within and adjacent to the Kalayaan Island Group and