Page "Demographics of the Republic of Ireland" Paragraph 2

However this changed dramatically with the Great Famine of the mid-19th century, which created conditions of mass starvation and emigration.

The famine was by far the most significant turning point in the demographics of the country, as not only did Ireland's population not grow for the next century, it continued a slow decline, the result of which is that the Republic of Ireland has a significantly smaller population today than would be expected for a European country of its size.