The RUC was established in 1922, years after the British Parliament's passage of the Government of Ireland Act to create Northern Ireland. A force of special constabulary was used in support of the RUC during the grave unrest which accompanied the establishment of Northern Ireland over the objections of the Roman Catholic minority in those counties. This Ulster Special Constabulary continued part-time until its replacement in 1970 by the present RUC Reserve. At the outset, in addition to fulfilling duties similar to those performed by other police forces in the United Kingdom, the RUC had military-type security duties, as its officers were subjected to shooting and bombing attacks from the illegal Irish Republican Army (IRA), which sought the state's downfall. From the early 1920's to 1957, the RUC had little difficulty in maintaining law and order in the Province. In 1956, the IRA and other terrorist organizations conducted another campaign of violence, which receded in 1962. Violence was renewed in the late 1960's and reached a peak in 1972 under the Provisional Irish Republican Army, which had broken away from the IRA. When it was apparent the RUC was not equipped to deal with the onslaught of violence, British troops were deployed in Northern Ireland in 1969. By the end of 1975, the RUC again became the primary instrument of social control. The manpower of the RUC has increased from 3,000 to 7,500 in just under 10 years. Its command structure and operational areas have changed to deal with the massive threats to public order. Advanced technology has been used to a high degree. Community relations have a high priority, as the RUC makes every effort to demonstrate to both Protestants and Roman Catholics that the law will be enforced without discrimination. The organization of the RUC is described in detail.