The Ulster Defence Regiment (UDR) was an infantry regiment of the British Army which began duties in 1970. Raised through public appeal, newspaper and television advertisements, with the operational role of "defence of life or property in Northern Ireland against armed attack or sabotage" but significantly not including "crowd control or riot duties in cities". The UDR, along with a new police reserve, replaced the Ulster Special Constabulary ("B-Specials"). It was the largest infantry regiment in the British Army, formed with seven battalions plus another four added within two years.