The right Red Hand of Ulster and the Flax [Linum usitatissimum] plant is shown on all stamps.

Face values:
3/4/5d: The Red Hand of Ulster within a Crowned six-pointed Star and a Flax [Linum usitatissimum] plant to symbolize the Irish linnen industry adorns the Queen's portrait.
6/9d: The Queen's portrait is flanked by a Flax plant on the left/right side and the Red Hand of Ulster is included in the Queen's portrait at bottom left/right enclosing the face value of the stamp.
1s3d/1s6d: A Flax plant at top left, Red Hand of Ulster at top right and a Ulster Field Gate, a charateristic feature of the Ulster countryside, at the bottom surrounds the Queen's portrait.

The Goverment of Ireland Act 1920 by the Parliament of the United Kingdom came into effect on on 3 May 1921 creating two self-governing territories within Ireland, with both remaining within the United Kingdom. Northern Ireland was formed from six of the nine counties of the historic Irish Province of Ulster with a majority of Protestant (Unionist) population. Southern Ireland was formed from the remaining three Ulster counties and the rest of the island.

The Anglo-Irish Treaty signed on 6 December 1921 concluded the Irish-British War. The Irish Island became independent as a self-governing Dominion , like Canada, Australia, etc.. The Irish Free State (1922 - 1937) was constituted on 6 December 1922.

Based on Article 12 of the peace treaty, Northern Ireland (established by the Goverment of Ireland Act 1920) seceded from the Irish Free State and became an official part of the UK which immediately changed its name to »United Kingdom of Great Britain and Northern Ireland«.

That fatal political decision was the catalyst for extreme tensions between the Northern Irish Catholic and Protestant population from the very first day on, again and again inflamed by Protestant hardliners. The peak of the conflict was reached from the late 1960s until 1998. The three decades, officially called »The Troubles« , were characterized by heavy violence, bloody riots and terror attacks from the paramilitaries of both of the hostiled parties. The main participants in the »The Troubles« were republican paramilitaries such as the Provisional Irish Republican Army (IRA) and the Irish National Liberation Army (INLA) ; loyalist paramilitaries such as the Ulster Volunteer Force (UVF) and the Ulster Defence Association (UDA) .

With pain and misery the British Armed Forces together with the Royal Ulster Constabluary (RUC) , common enemies for Irish republican and Ulster loyalist paramilitaries, could prevent a civil war in Northern Ireland.

The conflict was primarily political and nationalistic, fuelled by historical events. It also had an ethnic or sectarian dimension, although it was not a religious conflict. A key issue was the constitutional status of Northern Ireland. Unionists/loyalists , who were mostly Protestants, wanted Northern Ireland to remain within the United Kingdom. Irish nationalists/republicans , who were mostly Catholics, wanted Northern Ireland to leave the United Kingdom and join a united Ireland.

With the Good Friday Agreement , a multilateral and bilateral international agreement, signed on 10 April 1998, effective from 2 December 1999, a kind of peace in Northern Ireland could be achieved. At the present time the danger of a new outbreak of violence in Northern Ireland rises caused by the »Brexit« .