Michael Collins held the British Field Marshal Sir Henry Wilson (by then MP for North Down) responsible for the attacks on Catholics in the north and may have been behind his assassination in June 1922, though who ordered the shooting is unproven. The event helped to trigger the Irish Civil War. Winston Churchill insisted after the killing that Collins take action against the Anti-Treaty IRA, whom he assumed to be responsible. The outbreak of the civil war in the South ended the violence in the North, as the war demoralised the IRA in the north east and distracted the attention of the rest of the organisation from the question of partition. After Collins' death in August 1922, the new Irish Free State quietly ended Collins' policy of covert armed action in Northern Ireland.