Geo-genealogy of Irish Surnames

Kingston University London

The database of surnames for this map was derived from the 1890 census of Ireland at the county level (the finest available geographical descriptor). The county of birth of each surname was spatially joined with the centroid of the county boundary spatial data and the x- and y-coordinate geometry used to create a point feature class of surnames. The disperse markers algorithm in cartographic representations was used to randomly disperse points to place overlapping points away from their coincident x,y coordinates.

Surname labels were constrained to county polygons and conflict-resolution settings applied to ensure good distribution, no overlaps, and to accommodate different label sizes based on the census count attribute. The resulting map shows surnames as a geolocated proportional symbol to provide information on the historical geography of Irish surnames as well as quantitative birth counts from the 1890 census.

The basemap comprises a high-resolution digital elevation model, clipped to the Irish coastline and rendered using hypsometric tinting and hillshading. A hydrology layer completes the topographic basemap and a further iteration of surname placement accounts for the location of lakes and other major water bodies. These are deliberately not labelled to ensure that only surnames occupy the map.

Surname typeface and marginalia have been designed using a Celtic theme to support the map theme. The map won the most unique and people’s choice awards in the 2009 Esri UC Map Gallery as well as the Cartography Special Interest Group best map award.

Courtesy of Kenneth Field, Centre for GIS, Kingston University London.

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