Explores the political brinkmanship and bitter communal violence that led to the partition of Ireland.

On the 22nd June 1921, King George V and Queen Mary arrived in Belfast for the official opening of the first Northern Ireland parliament. Fearful for their lives, they had come to a city scarred by bitter sectarian violence.

The King's visit to Belfast was the culmination of three centuries of history - and three years of political brinkmanship and brutal communal violence. The occasion marked the creation of the new state of Northern Ireland. A line had been drawn on the map - a new border that separated the north and south of the island.

One hundred years on, this is the story of the dramatic events that led to the partition of Ireland - one that continues to reverberate to the present day and to dominate relationships between the islands of Britain and Ireland.