Saturday 16 November 2013

Tracing my Irish ancestors in 19th-century tax records

Elizabeth Mahon, who married Michael Byrne in 1894, was my great grandmother and the only child of James Mahon. James was born in 1823 and died in 1903. His father was Patrick Mahon, who was born about 1784 and died in 1865. They came from Yellow Walls, a townland in Malahide, Co. Dublin. I grew up in the same house that Elizabeth lived and died in; a house that has allegedly been passed down in our family since the mid-nineteenth century. While the lineage back to Patrick has been ‘proven’ by ‘conventional’ means, it was still interesting to trace it through Irish property-tax records.

Griffith’s Valuation is a mid-nineteenth century survey of property occupiers in Ireland. It was a taxation scheme, implemented to calculate how much a person should pay, based on the value of their holding. For each holding, it recorded the occupier’s name, the immediate lessor’s name, the acreage and the annual valuation of the buildings and land. The Valuation, with accompanying maps, is now freely available online and the lists for Malahide date to 1848 and 1850.
[1] Griffith listed a number of people named Mahon in the townland of Yellow Walls, all tenants of Lord Talbot, of Malahide Castle fame:
Yellow Walls Mahons, listed in Griffith’s Valuation, 1850

Knowing the area well, it was easy to pin-point our exact location on the ordinance survey map. Plot number 50, as highlighted below, was definitely ‘ours’.
Mahon property, Yellow Walls, Malahide, mid-1850s

I expected to find my great-great-great-grandfather listed and, sure enough, in 1850 a Patrick Mahon rented three acres, two roods and sixteen perches, roughly the expected sized plot. (There are forty perches in a rood and four roods in an acre.) The holding included a house and shed. However, Griffith indicated that Patrick was at map number 44, not 50 as expected. An unknown Francis McCann rented our plot 50, which made little sense.

Until the 1970s, regular revisions were made to the lists for each townland, to update them for changes in occupier, lessor, acreage and valuation. These handwritten changes, colour-coded by year of amendment, were recorded in manuscript books.  New books were opened as necessary and the Cancelled Valuation Books for Malahide are now held in the Valuation Office in Dublin. It is therefore possible to trace the chain of ownership, from the time of Griffith’s Valuation to near enough the present day.

The earliest Cancelled Valuation Book for Malahide commenced in 1855, five years after Griffith’s Valuation. It recorded Patrick Mahon’s holding of three acres, two roods and sixteen perches, but referenced it to map number 50 in Yellow Walls.  This better matched expectations, indicating that the map itself had been revised after Griffith’s Valuation had been published.

In this oldest book, ‘Sen.’ (senior) had been inserted after Patrick’s name, sometime after 1855. Later still, James Mahon Jun. (junior) replaced Patrick as occupier of this plot. According to the key at the start of the book, the red ink indicated this occurred in 1868. Patrick’s death certificate confirmed he died on 6 December 1865.
Mahon, excerpt from Cancelled Valuation Book, 1855-1902

The Cancelled Valuation Book for 1902-1945 recorded that Michael Byrne replaced James Mahon Jun., in 1905. James Mahon had died on 2 February 1903, according to his death certificate. Michael Byrne was his son-in-law. Michael died in 1927, around the time his eldest son, my grandfather James Byrne, was recorded at plot number 50.
Byrne, excerpt from Cancelled Valuation Book, 1945-1960

From a precursory look at the other Mahon holdings in Griffith’s, it is most unlikely that James Mahon Jun., with 5 acres, 3 roods and 37 perches, was Patrick’s son. It is also unlikely that James Mahon Sen. was Patrick’s father, as he was replaced by a Patrick Jun. after 1855. They were all probably related somehow and another trip to the Valuation Office may enable their relationship to be established.

Sources available on request.


© 2013 Black Raven Genealogy


  1. Welcome to Geneabloggers. I'm new to Geneabloggers also, and a new fan of your blog. Wishing you the best of luck with your genealogy certificate.

    Warm regards, Deb (
    (My husband is of Irish descent and we visited Dublin and County Cork a few years back. We all loved it. Absolutely beautiful countryside.)

  2. Welcome to Geneabloggers. My blog is listed along with yours today, on the Geneablogger "new blogs" page. I have ancestors from Ireland and have never delved very deep into their history. Only because of the difficulty I heard about Irish records. I hope that your blog will help me to learn more.
    Best of luck with your blog ( )

  3. Hi ladies, thank you for your kind welcome and for taking the time to comment. Diane, Irish research gets some bad press, not altogether deserved - there are plenty of record sources to keep it interesting, although it would be nice to have the census returns back to 1821.

    Happy blogging,


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