For a hundred years, GCHQ - Government Communications Headquarters - has been at the forefront of innovation in national security and British secret statecraft. Famed for its codebreaking achievements during the Second World War, and essential to the Allied victory, GCHQ also held a critical role in both the Falklands War and Cold War. Today, amidst the growing threats of terrorism and online crime, GCHQ continues to be the UK's leading intelligence, security and cyber agency, and a powerful tool of the British state.