The RAF had three major combat commands based in the United Kingdom: RAF Fighter Command charged with defence of the UK, RAF Bomber Command (formed 1936) which operated the bombers that would be offensive against the enemy, and RAF Coastal Command which was to protect Allied shipping and attack enemy shipping. The Royal Navy's Fleet Air Arm operated land-based fighters in defence of naval establishments and carrier-based aircraft. Later in the war the RAF's fighter force was divided into two Air Defence of Great Britain (ADGB) for protecting the UK and the Second Tactical Air Force for ground offensive support in the North West Europe campaign.