<p>Initially tasked with combatting the threat of Irish republican terrorists in the reign of Queen Victoria, the Metropolitan Police Special Branch went on to play a major role in the defence of the realm for over 120 years. Over time, 'the Branch', as it came to be known, assumed a much wider role, and was held responsible for monitoring the activities of anarchists, Bolsheviks and even the suffragettes. Later, it became the executive arm of MI...