On 4 March 1804, the New South Wales Corps was called into action to put down the Castle Hill convict rebellion. Also known as the "Irish Rebellion" and sometimes the second "Battle of Vinegar Hill" in reference to the uprising which took place in Ireland during the Irish Rebellion of 1798, it was a rebellion against British colonial authority that occurred when Irish convicts, led by Phillip Cunningham and William Johnson, along with many hundreds took up arms at Castle Hill and marched towards Parramatta, expecting support from the 1100 convicts from the river flat settlement at Green Hills, today's Hawkesbury. In response, martial law was declared and a detachment of 56 men from the New South Wales Corps under the command of Major George Johnston, marched all night to Parramatta and then pursued the rebels to near the modern Sydney suburb of Rouse Hill, where they engaged with the main rebel force consisting of about 230 to 260 men. A firefight followed between well trained and armed soldiers and the convicts after which the rebels dispersed. By the time that the fugitives had been chased down over the following days, at least 15 rebels had been killed and six were wounded, while another 26 had been captured, according to official records. Nine rebels were subsequently hanged.