George Johnston was a key figure in putting down what rebellion by convicts against colonial authority in the Castle Hill area of the British colony of New South Wales?
George Johnston (British Marines officer):  After serving as adjutant to Governor Arthur Phillip, Johnston served in the New South Wales Corps and he was later a key figure in putting down the Castle Hill convict rebellion in 1804 and then the Rum Rebellion in 1808, the latter of which led to his court martial and subsequent cashiering from military service.
i don't know