The Easter Rising also known as the Easter (or 'Irish') Rebellion and referred to erroneously in some contemporary British reports as the Sinn Fein Rebellion - an armed insurrection staged in Ireland during Easter Week, 1916, mounted by Irish republicans who aimed to end British rule in Ireland and establish an independent Irish Republic (whilst the United Kingdom was heavily engaged in World War I). Liberty Hall - Headquarters of the Citizen Army, after bombardment.