1800
Irish parliament passes Act of Union, formally proclaimed on January 1, 1801; Kingdom of Great Britain and Ireland created with a single parliament. 

1823
Barrister Daniel O'Connell established the Catholic Association to press for full emancipation for Catholics and rapidly converted it into a political mass-movement.

1829
O'Connell's success forced parliament to pass the Catholic Emancipation Act, removing virtually all disabilities against Catholics. 

1845
Nationalist Young Ireland Movement founded; attempted insurrection in 1848 failed but the movement influenced later generations of nationalists. 

1845-1849
Successive failures of the staple potato crop led to famine; by 1851 starvation, disease, and emigration had reduced the population by a quarter.

1856
Foundation of the Irish Republican Brotherhood, or Fenians, a revolutionary movement that attempted a failed uprising in 1867.

1869
Disestablishment of (Anglican) Church of Ireland.

1875
Nationalist Charles Stewart Parnell elected to British parliament, where he pursued a policy of obstructionism with other Irish Home Rule MPs to draw attention to the demand for a separate Irish parliament.

1880
Parnell becomes leader of Irish Home Rule movement, combining it with demands for land reform. He subsequently converted British Prime Minister William Gladstone to the cause of Home Rule. First boycotts by Irish tenants against English absentee landlords.

1881
Coercion Act passed giving Lord Lieutenant of Ireland power to arrest anyone merely on suspicion of treason or intimidation.

1882
Assassination in Phoenix Park, Dublin, of Lord Frederick Charles Cavendish and Thomas Burke, respectively Britain's Chief Secretary and Under-secretary for Ireland, by militant nationalists in a protest against the Coercion Act. The subsequent Crimes Act made the provisions of the Coercion Act even more stringent. 

1885
Irish Unionist Party founded to fight against Home Rule. 

1886
Defeat of first Home Rule Bill presented by Gladstone's Liberal government with support of the Irish Party. 

1890
Parnell forced to retire from leadership of nationalists, after he was cited as corespondent in a divorce case. Nationalist movement factionalises.

1891
Second Home Rule Bill defeated. Death of Parnell.