When British troops first deployed to Northern Ireland in 1969, to halt the threat of a new rising force - the Provisional Irish Republican Army - they could not have known that the longest campaign in the British Army's history was beginning.

While patrols, vehicle bombs and incendiary speeches are the defining memories of the Troubles, the real war was fought out of sight and out of mind. For thirty years, Britain's Special Forces waged a ferocious, secretive struggle against a ruthless and implacable enemy.

Harry McCallion offers a unique insight into nearly every major military action and operation in the Province, having served seven tours with the Parachute Regiment, passed selection for 14 Intelligence Company, completed six years with the SAS anti-terrorism team, and joined the Royal Ulster Constabulary, receiving two commendations for bravery during his service.

This book is his blistering account of the history of Britain's war against the IRA between 1970 and 1988 - the most murderous years of the conflict - drawn from his own operational experience and backed by first-hand accounts and unpublished documents. From new insights into high-profile killings and riveting accounts of enemy contact, to revelations about clandestine missions and strategies in combating a merciless enemy, Undercover War is the definitive inside story of the battle against the IRA, one of the most dangerous and effective terrorist organisations in recent history.