Second World War Germany and Russia invade Poland on September 1 1939. Eire declares its neutrality the following day and British PM Neville Chamberlain declares war the day after. Northern Ireland's shipyards, industries and agriculture are directed towards the war effort.

Irish leader Eamon de Valera rejects requests from Britain to use the former 'treaty ports' as naval bases.

In 1940, just before the fall of France, Chamberlain's government considers offering a united Ireland in exchange for Eire entering the war on the Allied side. Ulster Unionists outraged and de Valera rejects the suggestion.

German air raids on Belfast intensify in spring 1941 - nearly 1,000 people are killed and more than 2,000 are wounded. Aid is sent from Eire.

At the end of the war, de Valera expresses formal condolences to Germany on the death of Hitler - outrage in Britain and Northern Ireland.

British PM Winston Churchill, in his radio victory speech, makes a point of praising Northern Ireland's loyalty and criticising Eire's neutrality.

In the post-war election, only one Labour MP is returned in Northern Ireland, despite the landslide in the rest of Britain.

The Republic of Ireland The new Irish prime minister, John Costello, announces in Spetember 1948 that Eire is to become a republic outside the Commonwealth. This becomes fact in April 1949.

'Chapel-gate' election A Northern Ireland general election is held in February 1949 the shadow of the impending birth of the Irish Republic.

Collections are held at churches in Eire to support the campaign - hence the poll's name. There are violent sectarian clashes and the Unionists tighten their hold.

Ireland Act Attlee's government passes an act in June 1949 guaranteeing that Northern Ireland will remain part of the UK unless its parliament decides otherwise. The Act also gives Irish citizens special status, like Commonwealth citizens.

Flags and Emblems Act Interference with the Union Flag is forbidden from April 1954 and the legal display of the Republic of Ireland tricolour made difficult.

Internment IRA bombing and shooting campaign - 'Operation Harvest' - in border counties starting in December 1956 leads to internment without trial in the Republic and Northern Ireland.

The campaign is eventually called off by the IRA in 1962 because of lack of support.

Terence O'Neill inspects the troops

O'Neill Terence O'Neill becomes Prime Minister of Northern Ireland in March 1963, promising to transform the province and build bridges between the two communities.

Inequality The Campaign for Social Justice is launched in January 1964 in Dungannon to campaign for greater fairness for Catholics in employment and housing.

Taoiseach Sean Lemass becomes the first Irish Taoiseach to visit when he meets O'Neill at Stormont in January 1965. Afterwards, he says "a road block has been removed" but many Unionists are unhappy that the visit was kept a secret.

O'Neill visits Lemass in Dublin the following month and in December 1965 an Anglo-Irish free trade treaty is signed.

Easter Rising anniversary The 50th anniversary is celebrated in April 1966 in the Republic and also by Catholics in the North - though only with police protection against Unionists.

UVF Militant loyalists revive the Ulster Volunteer Force, declaring war in the IRA.

In May, the UVF targets a Catholic pub but mistakenly kills a Protestant woman; in June it murders a Catholic man and is outlawed.

Rights The Northern Ireland Civil Rights Association is founded in January 1967.

Republican clubs banned in March.