Simplify the following text for a Grade 11 native English-speaking person.
Original: The Irish Republic ( or ) was a unilaterally declared independent state of Ireland proclaimed in the Easter Rising of 1916 and formally established on 21 January 1919 by DÃ il Ã ireann .
Simplified: The Irish Republic ( Irish : SaorstÃ t Ã ireann ) was a declared independent state of the United Kingdom in the Easter Rising of 1916 and established in 1919 by the First DÃ il .