Bob Spiers
LostCousins Superstar
I found these interesting maps posted on Facebook 'The Brehon Academy' depicting the old and new Ireland as it related to Ancient Divisions compared to the new. The maps are self explanatory, but read the text below the maps which explains how MEATH (the 5th division) was later absorbed into LEINSTER, part of which is County Westmeath.

Along with Ulster, Munster, Leinster, and Connacht, Meath was once a provincial kingdom of Ireland. And it was perhaps the most significant of the five since it was here that the Ard-Rí or High King of all Ireland sat at the Hill of Tara.
It was also the home of the Hill of Uisneach and Ail na Míreann; the 'stone of divisions', considered the meeting point of the five provincial kingdoms, and 'navel of all Ireland'. Now found in county Westmeath; a placename derived from the fact that it was once simply the western part of the provincial kingdom of Meath.
Even in today's Ireland of just four provinces (Ulster now largely Northern Ireland) the Irish word for a province is still 'cúige', meaning a 'fifth'.

Along with Ulster, Munster, Leinster, and Connacht, Meath was once a provincial kingdom of Ireland. And it was perhaps the most significant of the five since it was here that the Ard-Rí or High King of all Ireland sat at the Hill of Tara.
It was also the home of the Hill of Uisneach and Ail na Míreann; the 'stone of divisions', considered the meeting point of the five provincial kingdoms, and 'navel of all Ireland'. Now found in county Westmeath; a placename derived from the fact that it was once simply the western part of the provincial kingdom of Meath.
Even in today's Ireland of just four provinces (Ulster now largely Northern Ireland) the Irish word for a province is still 'cúige', meaning a 'fifth'.