The Black and Tans
Empress Place, Summerhill North, headquarters of the Black and Tans in Cork city.
1920 began with the arrival in Ireland of new RIC recruits to supplement the native Irish force, then suffering from IRA attacks and widespread social exclusion. In 1920 the strength of the largely Irish-born force had been reduced by 3,229, half of those being resignations as well as 178 killed in action. The order for additional recruitment was issued on 2 January 1921 and by November of that year the force's numbers had reached 9,500. The per­sonnel were (mainly British) ex-soldiers and ex-sailors with service in World War One. Unemployed following the war, they were willing to become mercenaries for payment of ten shillings a day. Full uniforms could not be found for the first draft, so they wore dark green police hats and belts over khaki uniforms and made no attempt to hide their military nature. They first appeared on patrol in Upper Church, County Tipperary, the home of a famous pack of hounds called the 'Black and Tans'; that name was applied by locals to the new recruits and it stuck.

Selection process at recruitment was nearly as strict as for ordinary RIC officers. Some had a criminal record and most were men who were more than happy to engage in the reprisals that were initially condoned and eventually approved by the increasingly desperate authorities. The Black and Tans were badly trained and, apart from the 25% of them who were native Irish recruits, had no knowledge of the country in which they found themselves. Even the Irish recruits, who were mainly of Ulster origin, would have found Munster and west Connacht, the main places of deployment outside of Dublin, alien territory.

By the end of 1920 uniforms were standardised and it was impossible to tell the strangers from the regular RIC, except by accent and - more often than not - by their behaviour. In spite of the equally tainted reputation of the Auxiliary Cadets, who were first recruited in July 1920, the Anglo-Irish War eventually became known as the 'Tan war'.