Through the opium war, the pressure from foreign countries, Japanese invasions and foreign trade, China was pushed to reform to some extent; but overall, the main cause for the Revolution of 1911 was due to internal factors. Countless factors acted as contributors to this revolution, most of which were internal. Poverty, corruption, economic tensions, famines, floods and droughts swept through China, the failure to self-strengthen itself led to doubts about ‘the mandate of heaven’, and ultimately, the Taiping and Boxer rebellion emphasized how weak and overwhelmed China was and therefore not able to sustain itself.