Tsinghua University was initially founded as a preparatory school using indemnity funds paid by the U.S. after the Boxer Rebellion of 1900. It is one of China's most prestigious universities and a key member of the "C9 League". Tsinghua is consistently ranked among the top 20 universities worldwide. It is a global leader (often in the top 10) in Engineering and Technology fields (Computer Science, Civil Engineering, Environmental Science). The primary language of instruction is Chinese (Mandarin), but the number of Master's and PhD programs offered in English is increasing for international students (e.g., MBA).