Kingsley Shacklebolt was part of the Order of the Phoenix, the organisation formed as a defence against Voldemort and the Death Eaters. He is a very powerful wizard and for many years worked as an Auror - a dark wizard catcher - for the Ministry of Magic. During the Wizarding War, he was assigned to protect the British Muggle Prime Minister - who never realised Kingsley was a wizard. After the war, Kingsley Shacklebolt became the new Minister of Magic, ridding the Ministry of corruption and restoring peace and order.