The 2012 Constituency Commission report has recommended a reduction in the number of Da ́ il deputies from 166 to 158 and the number of general election constituencies from 43 to 40, while bringing about changes – some very fundamental in scope – to the majority of the existing Da ́ il constituencies. These changes are detailed in this article, while being placed in the context of previous electoral boundary amendments throughout the history of the Irish state and the processes employed in other states, such as the United Kingdom. The oft quoted contention that the 2012 boundary revisions are the most consider- able in scope since those of 1980 is tested and proven with reference to the use of the Kavanagh index of constituency change (KICC scores), with these KICC scores also employed to high- light the regions and constituencies that have been most prone to boundary amendments over the past three decades.