The events of the Easter Rising occured mostly in Dublin city, from April 24th until April 30th, 1916. The Dublin group consisted of 1,200 men and women from the nationalist militia the Irish Volunteers, the socialist trade union group Irish Citizen Army and the women’s group, Cumman na mBan. Its purpose was to end British rule in Ireland and establish an independent Irish Republic. But the British army quickly suppressed the Rising, and most of the leaders were executed following courts-martial. While at the time, the rebellion was not widely supported in Ireland, it eventually helped to increase the strength of the radical nationalists in Sinn Fein. Sinn Fein then went on to win three by-elections in 1917 and a general election in 1918, leading to their proclamation of an Irish Republic and the start of the Irish War of Independence.
This year, 2016, marks 100 years since the Easter Rising, and that anniversary will be celebrated all year, throughout all the Republic of Ireland. Here are some useful links that will give you a good idea of what events will be occuring throughout the country:
The Irish Times List of Events