Peel's pioneering ideas regarding the establishment of a uniformed, civil police force were refined against this background, in response to the prevailing lawlessness. As a result of initial opposition in parliament the plan Peel developed for a police force in Ireland first found expression in a diluted form in the Peace Preservation Act of 1814, which empowered the Lord Lieutenant to send a chief magistrate and a specially appointed body of armed men to any part of the country 'proclaimed' to be in a state of disturbance. On 5th August 1822 the Constabulary Act was passed and a new force called the Constabulary Police was formed. This Act for the first time allowed for the systematic establishment of an organised police force on a national basis. (Therefore, whilst Peel is principally remembered for his role in the founding of the London Metropolitan Police in 1829, credit with being the first organized police force in the British Isles nevertheless remains with the constabulary in Ireland.)

By 1836 this force had grown to around 5,000 men and by 1841 this had risen to a total of over 8,600. and from its inception the Irish constabulary was a barracked force. It was spread thinly throughout the country, with four or five policemen living in each barrack the norm.

Ireland in the first half of the nineteenth century was the pioneer for policing, acting almost as a laboratory for its development. With Irish society volatile, disordered and disorderly, the establishment of a uniformed, professional police force for the maintenance of law and order was an absolute necessity. It was the nature of collective violence and the weakness of previously existing forces for social control that led successive governments, from the early 1800's on, to press ahead with the establishment of a centrally controlled armed constabulary. The constabulary in Ireland served as a model for the establishment of a policing system in the rest of the British Isles, and ultimately even further afield in the developing colonies of the Empire. Throughout the 19th century the constabulary continued to develop as a police force. The evolution of the force was characterised by improvements in rank structure, training, and the rules and regulations governing the duties, conduct and discipline expected of the men. One of the most significant developments in the history of the constabulary during the 19th century was its redesignation as the Royal Irish Constabulary, making it the first 'Royal' police force in the British Empire.

Life in the constabulary during the 19th century could certainly, on occasions, be difficult. There was periodic agrarian unrest and constant simmering discontent in relation to the land question, particularly in the south and west. Indeed the dominant image of the R.I.C. for many people often stems from its responsibility to give protection to bailiffs executing distress warrants and evicting tenants, an unpleasant duty that was greatly disliked by members of the force (most of whom were themselves from a rural background). Nevertheless, the duties of the averagepoliceman were otherwise usually varied and uncontroversial.

These extensive civil and local government duties as well as routine patrolling in their districts ensured that the police constable was a very familiar part of daily life, someone with whom people would expect to have regular contact. It was the constable's job to acquire a thorough knowledge of his district and good relations with the local community made this easier. Indeed, good community relations, then as now, were essential for effective policing.

By the end of the 19th century there was a total of around 1,600 barracks dotted around the Irish countryside and some 11,000 constables. The territorial division of county and district on which the command structure had been based since the 1836 reorganization continued throughout the life of the R.I.C. Each county was supervised by a county inspector, with the counties sub-divided into a number of districts, each headed by a district inspector. They in turn were assisted by a head constable based at the district headquarters, on whom rested the main responsibility for operational policing and the conduct of the men in the barracks. There were a number of barracks in each district, usually with a sergeant and four constables.

The R.I.C. was characterised by a strict code of discipline. There was no official system of duty, rest days or annual leave, and in the interests of political impartiality members were even banned from voting at parliamentary elections. There were strict instructions laid down in police regulations concerning standards of conduct and appearance (for example, at one time police were absolutely prohibited from entering a public house socially). Other regulations were principally designed to maintain the standing of the police within the community. Members were forbidden to marry until they had at least seven years service and any potential bride had to be vetted by the constabulary authorities to ensure her social suitability. It was forbidden for policemen and their wives to sell produce, take lodgers or engage in certain forms of trade (for example, wives could be dressmakers but could not employ apprentices).