A series of gold rushes beginning in the early 1850s led to an influx of new migrants from China, North America and continental Europe, and also spurred outbreaks of bushranging and civil unrest; the latter peaked in 1854 when Ballarat miners launched the Eureka Rebellion against gold license fees. Between 1855 and 1890, the six colonies individually gained responsible government, managing most of their own affairs while remaining part of the British Empire. The Colonial Office in London retained control of some matters, notably foreign affairs and defence.