Modern archaeology has a relatively short history in China; it was not until the 20th century that systematic excavations of archaeological sites were undertaken.   The first excavations, in the 1920s and 1930s, were led by foreign archaeologists and yielded rich discoveries that encouraged Chinese scientists to enter the new field themselves.  In addition, the People's Republic of China, with its ideological commitment to a materialist view of history, has favored archaeological research.